Are you smarter than a 12-year-old? \ stacker news ~science

pull down to refresh

Are you smarter than a 12-year-old?

178 sats \ 17 comments \ @cryotosensei 12h science

view all related items

24 sats \ 8 replies \ @BeeRye 12h

10 square cms ?

55 sats \ 7 replies \ @cryotosensei OP 12h

Does my working make sense?

AC + BD = 20cm

Assign point between A and C to be X

AX + CX + BD = 20cm Since the difference between the perimeter of shaded part and unshaded part is 12cm, AX = 6cm CX = 4cm

Area of shaded part = 1/2 x 4 x 10 =20 cm2

48 sats \ 3 replies \ @BeeRye 11h

Mmm i misunderstood...was thinking the difference as in 40 - 12 = 28 for non-shaded perimeter, 12 for shaded. So then 2*10 = 20 / 2 = 10 cm2.

That is some hard math for a 12 year old! Although it's been a long, long time for me. I always enjoyed math, wish i had stuck with it more...

65 sats \ 2 replies \ @cryotosensei OP 11h

Same here. Now I have to relearn my Maths so that I can marshal my children through the education system.

This question is actually easy peasy because I can solve it. Thank you for the interest. Gives me the motivation to find those questions that have left me stumped. (I don’t even understand how to solve them after reading the worked solutions 🥲)

0 sats \ 0 replies \ @noknees 11h

😂

0 sats \ 0 replies \ @BeeRye 11h

my daughter is in kindergarten so i have seems a few more years before i get humiliated by her math abilities. I still appear as this all knowing wonder to her hahah

24 sats \ 2 replies \ @noknees 11h

Since the difference between the perimeter of shaded part and unshaded part is 12cm, AX = 6cm CX = 4cm

a big step jump...

0 sats \ 1 reply \ @cryotosensei OP 11h

Guilt as charged!

My working needed to be more elegant.

I ought to have done this ☝🏻

0 sats \ 0 replies \ @noknees 11h

yes that's more specific

79 sats \ 3 replies \ @Scroogey 11h

Perimeter unshaded:

10-x+10+10+y

Perimeter shaded:

x+y+10

Difference:

-2x+20=12

, so

x=4

Area shaded

A=(10*x)/2=20

21 sats \ 2 replies \ @cryotosensei OP 11h

Well done!

If I remember correctly, you homeschool your children? Do you teach them algebra when they were/are in elementary school?

24 sats \ 1 reply \ @Scroogey 11h

You mean based on #819532?

No, I don't. I have a child in (public) secondary school now. I'm helping with math homework and test preparation.

It has been harder than I initially imagined, and sometimes frustrating, because of how different they teach math now compared to my own childhood. Instead of mastering one thing at a time, then building on top of that with the next, now they always do multiple new things at the same time, then re-iterating over topics later (trusting it will eventually sink in). Sometimes it's tricky for me to even understand the tasks, due to new language invented.