Precision, Accuracy, Measurement, and Significant Figures

Поділитися
Вставка
  • Опубліковано 10 гру 2024

КОМЕНТАРІ • 220

  • @alleynewman1864
    @alleynewman1864 10 років тому +80

    Learned more in a 20 minute video than a quarter of chem class. Guess whos acing her exam? Thanks!!

    • @zackstone8822
      @zackstone8822 4 роки тому +8

      You ace that exam

    • @elitealphaviews8870
      @elitealphaviews8870 4 роки тому +4

      Zack Stone that was 5 years ago lol

    • @zackstone8822
      @zackstone8822 4 роки тому +2

      Elite Alpha Views yeah Ik 😂

    • @crimsondawn1996
      @crimsondawn1996 4 роки тому +2

      I hope you aced the exam :)

    • @hunterepicness4303
      @hunterepicness4303 4 роки тому +4

      @@crimsondawn1996 Why are we all commenting on a comment that is 5 years old? She's probably in her 3rd year of University rn

  • @alllisun5298
    @alllisun5298 3 роки тому +79

    It’s honestly kinda sad that i’m paying $400 each class on college just to teach myself with youtube videos and my professors just sitting back, doing nothing & getting paid for it…. Thanks for this video anyways.

  • @tb2748
    @tb2748 5 років тому +40

    This is way better than Khan Academy's explanation imo.

  • @WeloveMykeyJ
    @WeloveMykeyJ 6 років тому +4

    THIS WAS LIFE CHANGING!!!!!!!!!!!!! My professor is a dr. and he couldn't even explain this in a way that his class could understand it! I really appreciated the video and it completely helped me understand precision and sig figs! I even took notes to refer back to. thank you!!

  • @tydagoat6661
    @tydagoat6661 6 років тому +265

    Who teacher made them watch this

  • @gauravgoel2701
    @gauravgoel2701 3 роки тому +3

    I feel like after watching this video, my whole perception regarding measurements is changed!!! We live in an absolute imperfect world. Its all about the extent we can go for precision!!! ☑

  • @samuelhuggins7196
    @samuelhuggins7196 6 років тому +6

    Thank you SO much for this! I at first hesitated due to the length of the video, but having watched it I am VERY indebted. The discussion of significant numbers and measurements drove me crazy today when there were obvious inconsistencies on the material that our teacher provided. It is relatively easy to identify how many significant figures are in a number ALREADY DETERMINED, but to take a measurement yourself and determine how low one can designate the significant figures was not touched upon. I can sleep well now knowing that significant figures are all known numbers PLUS one estimated digit. WHY this wasn't in the textbooks is beyond me.

  • @rajasetlur6621
    @rajasetlur6621 6 років тому +7

    Excellent resource, prepared very thoughtfully and systematically! Thank you, sir!

  • @marciacuesta8887
    @marciacuesta8887 7 років тому +5

    I am a chemistry teacher and I must commend you on your accurate information, clear explanations and well presented video.

  • @rosietait6791
    @rosietait6791 7 років тому +4

    THIS VIDEO TAUGHT ME MORE IN 20 MINUTES THAN MY TEACHER DID IN 5 CLASSES

  • @kaylafernandes7390
    @kaylafernandes7390 5 років тому +1

    THIS SAVED ME. THE PACIFIC ATLANTIC TRICK IS GENUIS. I LOVE YOU

  • @Macabresque
    @Macabresque 6 місяців тому

    This was the explanation I needed to help wrap my brain around this concept. Thank you!!

  • @johnholme783
    @johnholme783 2 роки тому +1

    Now I understand the significance of significant figures! Pun intended! Great video! Both comprehensive and easy to understand; thank you!

  • @debraj.6755
    @debraj.6755 10 років тому +20

    this video is amazingly creative with the metaphor of Pacific and Atlantic. Thanks a lot.

  • @ScienceJim
    @ScienceJim 2 роки тому +1

    Very well done. Great illustrations and slow and steady presentation. I'm using this with my class tomorrow. Thank you for your time to create this.

  • @charlottefu1869
    @charlottefu1869 6 років тому

    You explained really clear and you are an excellent teacher. Big thank you for saving my life!!!!

  • @Naolboy
    @Naolboy 10 років тому +8

    What a wonderful explanation!!

  • @peterthepig3791
    @peterthepig3791 8 років тому +15

    You helped me in my homework thanks😀

  • @HimiBaby
    @HimiBaby Рік тому +1

    You're doing God's work ❤

  • @bobbleheadeater3209
    @bobbleheadeater3209 7 років тому +75

    I guess that 007 agent was really just agent 7 all along.
    James Bond has lied to us all.

    • @marciacuesta8887
      @marciacuesta8887 7 років тому +2

      LOLOLOLOL!!! Awesome! You got it!

    • @JohannesMageroy
      @JohannesMageroy 6 років тому +2

      @@GPCTM You must be fun at parties

    • @GPCTM
      @GPCTM 4 роки тому

      what's a party?

  • @vincentt.6421
    @vincentt.6421 6 днів тому

    Sir your measuring object section was amazing I had a question on this exact topic but didn’t practice this beforehand

  • @taff_2024
    @taff_2024 3 роки тому +1

    Excellent explanation. Worth watching.

  • @09.asitasinghrajput99
    @09.asitasinghrajput99 4 роки тому

    Iam in love with the way you explained it!! You explained each and everything so clearly.....😊

  • @jotarokujo4775
    @jotarokujo4775 3 роки тому

    thank you sir! learned this stuff for only 20minutes . lot of helped . earned a subscriber definitely!

  • @tega_ovi1
    @tega_ovi1 2 роки тому +1

    I really enjoyed this video and understood every concept. Thanks 😊😊

  • @meekaandrews8210
    @meekaandrews8210 3 роки тому

    I wish this guy was my teacher I learned this quicker than my teacher.Now I can go ace my Lab Techniques exam!

  • @ItzLake
    @ItzLake 9 років тому +17

    YOU SAVED MY LIFE!!!!!!!!!!

  • @anniesimrin2116
    @anniesimrin2116 4 роки тому

    first class teaching fascinating ideas
    tnq sir

  • @Zarnab-n4o
    @Zarnab-n4o 4 роки тому

    Wow so exciting ✔
    It helped me to clear my concepts which were confused by me bcz of my classfellows 💚

  • @graciehines9468
    @graciehines9468 4 роки тому +1

    I learned more in 20 minutes then I have in 2 weeks

  • @hamidrezaseilabadi839
    @hamidrezaseilabadi839 4 роки тому

    Thank you for making this, the details were very useful.

  • @777dnangel
    @777dnangel 9 років тому +5

    I have something to clarify, at 7:48, I am quite bothered with the usage of the word "precision" or the words "more precise", I think the better word to be used is accurate or more accurate, am i right? I hope anyone would clarify my dilema with this concept :) thanks

    • @mrfarabaugh
      @mrfarabaugh  9 років тому +12

      Norman Dañez Accuracy refers to how close a measurement is to the true value. There is no difference in accuracy between 6 cm, 6.0 cm, and 6.00 cm. They are all the same, in terms of their numerical value. On the other hand, precision refers to a set of measurements and how close they are to each other. When the word "precise" is used to describe a measurement (or a ruler in this case), it refers to the fact that there is a small range of error. A measurement of 6 cm can fall between 5 cm and 7cm. A measurement of 6.00 cm falls between 5.99 cm and 6.01 cm. Therefore 6.00 cm is more precise than 6 cm because there is a smaller range of error.

    • @bolso66
      @bolso66 9 років тому +2

      +Michael Farabaugh Can one say that the second and third rulers have a better resolution and therefore the measurement is more accurate (rather than precise)? If I understood right precision refers to a set of measurements not to one single measurement as in the video?

  • @lindaginn7714
    @lindaginn7714 3 роки тому

    Excellent video!

  • @leraheva8485
    @leraheva8485 Рік тому

    Excellent video. Thank you

  • @alieubah3317
    @alieubah3317 4 роки тому

    thanks soo much ,helped me in my chemical analysis course

  • @kijboli
    @kijboli 9 років тому +1

    Wonderful explanation

  • @dedriannehartgers629
    @dedriannehartgers629 7 років тому

    Thank you for this video, it is a big help for my 9th grade Physical Science Lab on escience lab

  • @saulbah3661
    @saulbah3661 6 років тому +1

    what software do you use to make these presentations, such as the animations with the dartboard. Thank you.

  • @sahyofeels2616
    @sahyofeels2616 3 роки тому +2

    Wait so if I had a ruler only marked at 1 and at 10 and I estimated it at 7, would 7 be significant???

  • @riyagupta6408
    @riyagupta6408 7 років тому +1

    You saved my lab!!

  • @kweenny5224
    @kweenny5224 5 років тому

    Perfect video. Love it. ❤ Thank U 😘

  • @tiktokmixer4885
    @tiktokmixer4885 3 роки тому

    thx bro you teach better than my teacher, my teacher gives out work and expects us to know it LOL

  • @snowmike159
    @snowmike159 2 роки тому

    love this video, it is helpful for me, tysm

  • @FahadAli-bp4zb
    @FahadAli-bp4zb 8 років тому +1

    Thank u very much for the pure explanation ❤️❤️❤️

  • @IRLocopilot1853
    @IRLocopilot1853 7 років тому

    extraordinary explanation

  • @video13522
    @video13522 9 років тому +6

    Love how you explain it !

  • @bluesky-op2ng
    @bluesky-op2ng 8 років тому

    The best video big thumps up :)))))))))

  • @san7071
    @san7071 6 років тому

    Taking notes on the first 10 min for my class......

  • @mesutbakhtyari
    @mesutbakhtyari 5 років тому

    Nice explanation

  • @JasonRichardTesch
    @JasonRichardTesch 7 років тому

    So, for the example at 5:00 the measurement would be recorded 6 ± 5cm ?

    • @mrfarabaugh
      @mrfarabaugh  7 років тому

      I would say that a reasonable person could estimate the length of any object on that particular ruler to within ± 2 cm of the actual measurement. If we assume that the uncertainty is ± 2, then I would say the measurement of the pencil would be recorded as 6 ± 2 cm.

    • @chruszczowskibrzeczyszczyk707
      @chruszczowskibrzeczyszczyk707 6 років тому

      Michael, you are inconsistent with your statements. Once you are saying that you measure to the one tenth of the scale (so in the case that we have ruler with marks at 0 and 10 cm, we can read up to 1 cm). But above you are saying that with particular ruler one can measure to within ± 2 cm. So which is right???
      My answer to that question is - NEITHER.
      With the ANY ruler or scale you can read ONLY up to the HALF of the smallest grading. So, in the above example at 5:00 min, the readout can be done to within 5cm (one half of the 10 cm); that means that the correct answer is: 5 cm ± 5cm
      Of course it means that one should use different ruler to measure that pencil.
      As a rule of thumb - with any ruler/scale one can measure/report value ONLY up to the HALF of the smallest grading (unless Vernier scale is there). That is because the Manufacturer of the ruler made it in such a way that we can be sure only up to the half of the scale marks. Otherwise producer would put more lines for me. The reason there is no more lines b/c they are uncertain!!!!

  • @rachelfaithmanning
    @rachelfaithmanning 6 років тому

    This video was very helpful to me! I'm curious to know what grade this is for? Thank you!

    • @mrfarabaugh
      @mrfarabaugh  6 років тому

      High school chemistry (10th grade)

  • @kathygabriel627
    @kathygabriel627 4 роки тому

    Very nice! I really will use this1

  • @justphysics9545
    @justphysics9545 4 роки тому

    Thanx . You made it clear to me

  • @RadioBiafraTvNwaChineke
    @RadioBiafraTvNwaChineke 3 роки тому

    Thank you very much, it is quite helpful.

  • @mmflowclo7319
    @mmflowclo7319 2 роки тому

    you should make a updated version of this video with time stamps and better visuals.

  • @ravenship2486
    @ravenship2486 6 років тому +1

    I have doubt regarding measuring pencil length. E.g. if scale has 2 measuring number 0 and 10 then the length of pencil should 0 cm long. How could it be 6cm? Similarly a scale has least count 1mm from ranging 0 to 10 cm then it can only show length of pencil 6.7 cm , then how can it be 6.75 cm?

    • @mrfarabaugh
      @mrfarabaugh  6 років тому

      Your final digit is the estimated digit, which is one power of ten smaller than the divisions that are marked on the ruler. If the length of the object falls somewhere between the marks at 0 cm and 10 cm, the final digit in your estimate of length should go to the one's place (for example: 6 cm). If the length of the object falls somewhere between 6 cm and 7 cm, the final digit in your estimate of length should go to the tenth place (for example: 6.5 cm). If the length of the object falls somewhere between 6.7 cm and 6.8 cm, the final digit in your estimate of length should go to the hundredth place (for example: 6.75 cm).

  • @a_kid5207
    @a_kid5207 3 роки тому +1

    yes

  • @haniahcomonog7128
    @haniahcomonog7128 Місяць тому

    I LOVE YOU THANK YOU😫😫😫

  • @honeybarnwal9734
    @honeybarnwal9734 3 роки тому

    Nice video

  • @conorkilhenny5362
    @conorkilhenny5362 6 років тому

    What happens when a ruler is only accurate to 1/2 of a centimeter and the thing I'm measuring is really 4.43 cm? Do I round to 4.50 or do I put in two uncertain values?

    • @mrfarabaugh
      @mrfarabaugh  6 років тому

      In my opinion, I would still estimate the length of the object to the nearest 0.1 cm

    • @conorkilhenny5362
      @conorkilhenny5362 6 років тому

      Michael Farabaugh thanks

  • @spiritoflife655
    @spiritoflife655 2 роки тому

    Hey sir what is relation between accuracy and significant figures

  • @arslanashraf2617
    @arslanashraf2617 7 років тому +1

    excuse me ! I have a question which is more precise 5.41cm Or 5.412cm .Thank you.

    • @mrfarabaugh
      @mrfarabaugh  7 років тому +3

      A measurement of 5.412 cm is more precise than a measurement of 5.41 cm. If we assume that the final, estimated digit can vary according to ± 1, then 5.412 ± 0.001 cm is more precise than 5.41 ± 0.01 cm because it has a smaller range of uncertainty associated with it.

  • @DestinyJerry-xe2hd
    @DestinyJerry-xe2hd Рік тому

    Please I want more examples precision and accuracy

  • @bawalther2009
    @bawalther2009 3 роки тому

    Must read: Walther, B.A., Moore, J.L., 2005. The definitions of bias, precision, and accuracy, and their use in testing the performance of species richness estimators, with a literature review of estimator performance. Ecography 28, 815-829.

  • @guillermo.montoya9825
    @guillermo.montoya9825 3 роки тому

    Thanks teacher

  • @suvethasuvethasuvethasuvet5233
    @suvethasuvethasuvethasuvet5233 6 років тому +1

    Pls give me example for accuracy and precision

  • @anwaarbukhari3792
    @anwaarbukhari3792 9 років тому +1

    welldone

  • @RajendraPrasad-zc6kh
    @RajendraPrasad-zc6kh 2 роки тому

    Wonderful

  • @govindprajapat5261
    @govindprajapat5261 Рік тому

    Significant figures tells about precision or accuracy?

  • @nitishgogoi4028
    @nitishgogoi4028 4 роки тому

    Sir, i have a question. Sir in the number 36000 why the zeros are not significant ..if we take it as 36000 seconds...then all digits must be significant otherwise the measurement wouldnt make any sense

    • @mrfarabaugh
      @mrfarabaugh  4 роки тому

      Focus on the number, and not the unit. If the number 36000 has no decimal point at the end, then all we can say for sure is that we know this value to two significant figures. The actual value of the number could fall anywhere in between values of 35500 and 36499. If, on the other hand, we have a measurement of exactly 36000. we need to place a decimal point at the end of the number. This would indicate that the value is known to five significant figures.

  • @salemalshamsi4353
    @salemalshamsi4353 5 років тому

    Thank you 📝👍

  • @mahadevan7885
    @mahadevan7885 5 років тому +1

    Thanks a lot.....

  • @OLUWAMAYOWA.
    @OLUWAMAYOWA. 8 років тому

    Really helpful

  • @umuterdogan5735
    @umuterdogan5735 6 років тому +1

    Why can you say that the deviation in the number 5.412 is ± 0.001?
    As you explained, the "n.nn2" digit is estimated and therefore could range from 0 to 9, yielding in an absolute deviation d < ±0.01. Our measure's smallest division is actually 0.01 units, isn't it? I would suppose a deviation of d < ± 0.001 in 5.412 if I considered the number 5.412 as the median of this range: 5.4115

  • @shammaaltenaiji1321
    @shammaaltenaiji1321 9 років тому +7

    just curios what grade are everyone here in ?

  • @sighisoaraa
    @sighisoaraa 8 років тому

    So significant figures are related to precision in that they indicate how precise a number is.

  • @edent.4640
    @edent.4640 5 років тому

    we love mrs krug

    • @che1sxii
      @che1sxii 5 років тому

      eden wtf

    • @edent.4640
      @edent.4640 5 років тому

      @@che1sxii you CRACKHEAD

  • @AnthonyContreras.
    @AnthonyContreras. 6 років тому

    Huge help thanks!

  • @dlinzikri1766
    @dlinzikri1766 2 роки тому

    Thxs 👏

  • @shrimpgrll
    @shrimpgrll 3 роки тому

    thanks besti

  • @AbdallahAttiaA
    @AbdallahAttiaA 2 місяці тому

    here i am in 2024 still learning from the video thank you

  • @redechiko
    @redechiko 7 років тому

    can you define the meaning of equal precision measurement

  • @MariamAbdalla-rw8ki
    @MariamAbdalla-rw8ki 2 роки тому

    وايد تسولف ماشالله عليك

  • @lumazeidan9285
    @lumazeidan9285 7 років тому

    Thank you
    It makes sense to me

  • @rubyalfaro2576
    @rubyalfaro2576 7 років тому

    tysvm this clarified so much.

  • @charith12345
    @charith12345 10 років тому

    if we measure a value and it gives a value 200 and the intrument is caple of being accurate for the 10th position?????

    • @mrfarabaugh
      @mrfarabaugh  10 років тому

      It sounds like you want the measurement "200" to have exactly two significant figures. The only way to do this is to use scientific notation, as in 2.0 x 10^2

  • @sadiasi152
    @sadiasi152 5 років тому

    Thank you!!!

  • @ppscphysicspreparation2626
    @ppscphysicspreparation2626 6 років тому

    If an instrument has a L.C of 0.1 cm it means we can guess upto 100th place ten power one higher than the L.C, but if a scale has L. C OF 10 kg and a measurement like 8000 kg with this scale should have 2 significant figures but it has 3 S. F WHY? how?

    • @umuterdogan5735
      @umuterdogan5735 6 років тому

      If you weigh the 8000kg on a scale with 10kg division, then it shows up as 800. Then you have to add up ".n" , that is the estimated digit, e.g. it becomes the value 800.0 (x 10) kg. That yields to 4 sig figs. That is what I guess it should be.

    • @umuterdogan5735
      @umuterdogan5735 6 років тому

      If you follow this youtube video ua-cam.com/video/fo_QOB65D7k/v-deo.html, you will actually get your expected answer of 3.
      Let me calculate it briefly: The resolution is 10kg which is shown as 1 digit in the least signficant position. This digit is already the estimated sig fig, which is estimated by the scale for you. You must not estimate another digit. Also this least sig digit represents a range from 5 to 14 kg due to mathematical rounding to 10kg. Recap: The number "800." (x10) kg has 3 sig fig digits. Also listen carefully to this part of that video to get the explanation ua-cam.com/video/fo_QOB65D7k/v-deo.html . Hope this helps a bit.

  • @TheAlvinHuang
    @TheAlvinHuang 7 років тому

    Thanks!

  • @techasitsukhahuta1162
    @techasitsukhahuta1162 8 років тому

    Thank! U help me So... i can do the test next week :)

  • @elipsem1008
    @elipsem1008 4 роки тому

    The Pacific one is confusing can someone help

  • @windsunh2o
    @windsunh2o 5 років тому

    Okay, but what is the significance of significant figures? The zeros in a 1500 Liter measurement may not be significant, but they are definitely important. The number would be completely different without them. I don't see the point.

    • @mrfarabaugh
      @mrfarabaugh  5 років тому +1

      Suppose that the initial reading on a buret (with lines every 0.1 mL) is recorded as 1.52 mL. After dispensing some liquid from the buret, the final reading is recorded as 26.52 mL. How much liquid was delivered from the buret?
      Now imagine that you have liquid in a beaker (with lines every 10 mL). The volume of liquid is roughly halfway between the 20 mL mark and the 30 mL mark. How should this volume be recorded?
      The buret delivered 25.00 mL (4 significant figures). The beaker holds 25 mL (2 sig figs).
      Significant figures give us information about the level of precision associated with the piece of equipment that was used to record the measurement.
      Since 1500 L (in your example) has only 2 sig figs, the volume could be somewhere between 1400 L and 1600 L. If you had said that the volume is 1500. L (4 sig figs), that narrows it down. The volume would be somewhere between 1499 mL and 1501 mL. A measurement of 1500. L is more precise than a measurement of 1500 L, because there is a smaller range of error.

  • @gabrieldecker7209
    @gabrieldecker7209 4 роки тому

    I could see the logics behind sig figs until he got to talk about numbers with leading zeros.
    I mean, if sig figs are all the known digits + estimated digit, why would the number 0.007 have only 1 sig fig? I mean, why those leading zeros are not "Known digits/ certain digits"?? If I take a ruler that is graduated in hundredths and I measure a tiny object, which does not even reach the 1 hundredth of a centimeter mark. Therefore, I can assure that this object measures 0,00cm (KNOWN/certain digits) and I can ESTIMATE that it has about 7 thousandths of a centimeter. Therefore, I could say that this object measures 0.007cm, which means that the zeros are the KNOWN digits, and the 7 is the estimated digit.
    Since sig figs are the known digits + estimated digit (8:45) , why would it be wrong to say that 0.007cm has 4 sig figs????

    • @mrfarabaugh
      @mrfarabaugh  4 роки тому +1

      A measurement of 7.0 cm has 2 sig figs, right? Okay, now let's convert that measurement of 7.0 cm into units of meters, or even kilometers. If we do that, we should still have the same number of sig figs. Doing those conversions gives us values of 0.070 m. and 0.000070 km. Yes, these measurements still have 2 sig figs. If we write them in scientific notation, we would get 7.0 × 10⁻² m and 7.0 × 10⁻⁵ km. They still have 2 sig figs.
      The scientific notation really illustrates the point that the leading zeroes in a measurement don't count as part of the sig figs. If you convert a measurement from regular notation into scientific notation, you should still have the same number of sig figs either way, as shown in these examples. Notice that the leading zeroes don't count, but the trailing zeroes do.
      0.007 cm = 7 × 10⁻³ cm (1 sig fig)
      0.0070 cm = 7.0 × 10⁻³ cm (2 sig figs)
      0.00700 cm = 7.00 × 10⁻³ cm (3 sig figs)

    • @gabrieldecker7209
      @gabrieldecker7209 4 роки тому

      @@mrfarabaugh Oh, I see. Nice explanation! But like, I still have some doubts. I mean, if we had 0.0070m, it would mean that we know FOR SURE (that is, certain digits/ known digits) that the object we are measuring has 0 ones , 0 tenths, 0 hundredths, and 7 thousandths of meter; Besides that, the digit zero(trailing zero) in the ten-thousandth is just an estimative.
      If what I just wrote is correct, then we would have four CERTAIN digits {0,0,0,7} and one UNCERTAIN digit {the trailing zero in the ten-thousandth place}. Where am I wrong, Sir?

    • @paakwekuandoh3586
      @paakwekuandoh3586 Рік тому

      @gabrieldecker7209
      If we had 0.0070 m, it could mean that:
      we used a metre rule to measure this distance. However, that is an overkill for the choice of measuring instrument for such a small distance and an imprecise measurement given that the metre rule has a precision of 1 mm.
      OR
      we used a micrometer screw gauge instead. The screw gauge gave us a more precise reading of 7.0 mm, which we recorded and then converted to 0.0070 m.
      It can be seen that 7.0 mm and 0.0070 m should have the same number of significant figures (2s.f.) because they refer to the same measurement written in different units.
      I just saw your question and I hope you find this helpful and relevant after 2 years. :D

  • @sandhyapatil6436
    @sandhyapatil6436 7 років тому

    00234000 has how many sigfigs?

    • @mrfarabaugh
      @mrfarabaugh  7 років тому +2

      I'm not sure why there are two leading zeroes in your number. If your number represents 234000 (two hundred thirty-four thousand) with no decimal point at the end of the number, then it has three sig figs.

  • @nawazkhokhar7726
    @nawazkhokhar7726 4 роки тому

    You Man. You know.

  • @stimulantdaimamld2099
    @stimulantdaimamld2099 3 роки тому

    great

  • @helena9148
    @helena9148 10 років тому

    You've got a bautiful voice. Just saying.

  • @newyorkisgay6694
    @newyorkisgay6694 8 років тому

    are teacher calls them significant digits

  • @경빈-h3o
    @경빈-h3o 5 років тому +2

    대한독립만세

  • @yeoj3637
    @yeoj3637 4 роки тому +1

    *PWC Brought me here...*