This simple math trick can be used to multiply any number by 5, 25 or 125 easily (and instantly!). To support tecmath on Patreon: / tecmath It really helps and is appreciated!
I've always kinda just done this for 5 and 25, but first multiplying by 10 or 100 and then dividing. Your way is better, because it's not as easy to slip decimals by mistake. And taking it to the next level, 125, is a good one too. I've actually used it most when I've had to work out how many hours are in a certain number of days. For a fortnight, say, thus 14×24, well, 14×25=350, easy-peasy lemon squeezie by your method, and then just bugger off the extra 14 to arrive at 336.
I was just looking for how to do trig and I came across an 11 year old vid of yours, the fact you still making these videos is amazing, I've never seen a channel be so handy, thanks for these vids.
@tecmath I don't know kw if you check comments but I want to say thank you. I homeschool my kids and often their curriculum makes things much more complicated than it needs to be. In fact, before I started homeschooling, my middle daughter got SO stressed and was left behind. I now check with your channel before EVERY lesson to find a way that SHE will understand. Thank you so much.
I'm in my 50s so I grew up more with mental arithmetic. This one I mostly worked out with myself, but a lot of other videos on this channel have made me do even more maths in my head. I just need to keep coming back to remind myself about them… good for the channel, I suppose. 😉 Anyhow, I hope it's not patronising for me to say that it's great to see somebody in their 20s appreciating this so much, too. Admittedly, these days when I have my hands full with a project and I need to do maths to work out whether I have enough wood or whatever, I just say 'Hey Google…' (this is especially useful here in the US, where so many products come in weird units that are difficult to work with-metric is _so_ much easier for mental arithmetic, that it's even more of a relief to see somebody in the US ('math') valuing this stuff!). But occasionally, I still find myself somewhere either too far or too noisy for a phone or watch or smart speaker to do the thinking for me. 🙂
Sorry to hear that. Sometimes, 'stuff' really sucks. I hope you can find someone to talk with about it; it can really help make you feel better, and then it's a bit easier to deal with. Hang in there and don't let the turkeys get you down.
I LOVE your channel SO much! Please never stop making this videos, this videos have helped me immensely in getting better at mental math :)
Thanks. This is a handy trick right? And really easy to do!
Also, if you want, you can times by 10 and divide by 2, or times by 100 and divide by 4. You can do multiplication first if that's easier for you
been binging your vids alot lately, great stuff
I've always kinda just done this for 5 and 25, but first multiplying by 10 or 100 and then dividing. Your way is better, because it's not as easy to slip decimals by mistake. And taking it to the next level, 125, is a good one too.
I've actually used it most when I've had to work out how many hours are in a certain number of days. For a fortnight, say, thus 14×24, well, 14×25=350, easy-peasy lemon squeezie by your method, and then just bugger off the extra 14 to arrive at 336.
Thanks for that.
Lemon squeezie? Or David Campese?
Always learning on this channel. Thanks for your time and genius.
This was so cool. Thanks
You can kina use this for anything! That's insane!
your video helped me so much to speed up my calculation to prepare for the oxford entrance exam, it is tomorrow, hope it goes well
I was just looking for how to do trig and I came across an 11 year old vid of yours, the fact you still making these videos is amazing, I've never seen a channel be so handy, thanks for these vids.
Wow your channel help me lot thankubso much ur channel is best
love this
mind blown 😮 I'm new here btw. this was super useful tysm👍
Welcome to the channel.
Glad you liked it.
@tecmath I don't know kw if you check comments but I want to say thank you. I homeschool my kids and often their curriculum makes things much more complicated than it needs to be. In fact, before I started homeschooling, my middle daughter got SO stressed and was left behind. I now check with your channel before EVERY lesson to find a way that SHE will understand. Thank you so much.
Thanks mate.
That is a lovely thing to say!
i wish i had maths teacher like u in school.
So Inspiring ❤❤❤
Mid 20s and still coming back for tips! Thanks my man
Thanks. :)
I'm in my 50s so I grew up more with mental arithmetic. This one I mostly worked out with myself, but a lot of other videos on this channel have made me do even more maths in my head. I just need to keep coming back to remind myself about them… good for the channel, I suppose. 😉 Anyhow, I hope it's not patronising for me to say that it's great to see somebody in their 20s appreciating this so much, too. Admittedly, these days when I have my hands full with a project and I need to do maths to work out whether I have enough wood or whatever, I just say 'Hey Google…' (this is especially useful here in the US, where so many products come in weird units that are difficult to work with-metric is _so_ much easier for mental arithmetic, that it's even more of a relief to see somebody in the US ('math') valuing this stuff!). But occasionally, I still find myself somewhere either too far or too noisy for a phone or watch or smart speaker to do the thinking for me. 🙂
perfect ❤.
exciting. easy. easy. 😊👍
Bro, I'm gonna a math wiz now
fun fact: these can be used to find 1/2, 1/4, and 1/8 of a number. just skip the x10 step!
Love your channel, but why do i have to double my normal volume to hear you?
👍👍
Damn shame maths weren't taught this way everywhere from the earliest grades.
2:26 Sir isnt that simply 23.5 × 10 😅
5:28 Same here.... 5.75 × 100
It is!
i just did (400+3)(120+5)
34 x 5:
What I do is (30 x 5) + (4 x 5)
Same answer 👍
(120 x 5) + (6 x 5)
who answer is the smartest
Hi
Hello. How are you going?
@@tecmath I am feeling miserable.
@@astema_Why is that?
@@RiverHeights Stuff.
Sorry to hear that. Sometimes, 'stuff' really sucks. I hope you can find someone to talk with about it; it can really help make you feel better, and then it's a bit easier to deal with. Hang in there and don't let the turkeys get you down.
Face reveal yourself Odinson