I’m not sure it works on me. Not because I’m some super human resistant to advertising (I’m not) but because I’m so bad at math that when they start asking me about anything involving small change I tune out and overestimate by 50% rounded into nice whole numbers.
“This is 19.99”
“Okay so it’s basically 30$.”
It gives me nice surprises sometimes when I get my receipt.
You can take 1% of anything, then multiply as well.
Like 7% of 15.50
1% is .155 (10% is moving decimal to left once, 1% is twice)
.155 × 7 = 1.083
That’s a hard one to do in your head, but .155 × 7 is easier to do on paper than 15.50 × .07.
Say something is 49.99 and 7% off. 1% is .5. .5 ×7 = 3.5. You could probably do that in your head. Otherwise, good luck trying to do 7% of 50 in your head.
Edit: Hmm. So you could also do 3.5% of 100 instead of 7% of 50. That would have been the easiest way to do that one.
Bonus: I thought I’d mention 11s. They are my favorite thing in math because they are so easy and you seem like a math wizard to anyone.
Say you have 42 × 11. That’s 462.
You just split apart the 4 and 2, add 4 and 2, then stick it in the middle.
I’m not sure it works on me. Not because I’m some super human resistant to advertising (I’m not) but because I’m so bad at math that when they start asking me about anything involving small change I tune out and overestimate by 50% rounded into nice whole numbers.
“This is 19.99”
“Okay so it’s basically 30$.”
It gives me nice surprises sometimes when I get my receipt.
You have to be, like, better at math to do that though?
Decimals are the devil’s work.
You can remove the decimal then add it back at the end
15.50
Is
1500
Half would be 775
Or 7.75
yep, and figure out what 20% of your bill is by taking 10% and double it. saves my ass every time i gotta tip lol
You can take 1% of anything, then multiply as well.
Like 7% of 15.50
1% is .155 (10% is moving decimal to left once, 1% is twice)
.155 × 7 = 1.083
That’s a hard one to do in your head, but .155 × 7 is easier to do on paper than 15.50 × .07.
Say something is 49.99 and 7% off. 1% is .5. .5 ×7 = 3.5. You could probably do that in your head. Otherwise, good luck trying to do 7% of 50 in your head.
Edit: Hmm. So you could also do 3.5% of 100 instead of 7% of 50. That would have been the easiest way to do that one.
Bonus: I thought I’d mention 11s. They are my favorite thing in math because they are so easy and you seem like a math wizard to anyone.
Say you have 42 × 11. That’s 462.
You just split apart the 4 and 2, add 4 and 2, then stick it in the middle.
Something like 67 × 11. Where the digits add >10.
6…7, 6+7=13, 6+1…3…7. So 737.
Using whole numbers can be easier when estimating