Speed Mental Math Exercise #shorts

This was a trend on IG/TikTok, people would write out how they solved this problem. It shows that there are many ways to solve a math problem, but let me show you a faster way than stacking and adding.

This is an easy problem to teach children to group numbers to add faster.
You will start writing this out, and after practicing for a few days or weeks the child will be able to do it in their head. The top kids in the top countries for math can do this in a fraction of a second! It's always my goal to have our kids be competitive on a global scale while also having fun while learning.

Age level: any age

Prior Knowledge: The child should know common ways to make 10 ( 0+10, 1+9, 2+8, 3+7, 4+6). The child should know how to add multiples of 10 (For example 40 + 20 or 80 + 50).

93 + 97 = 190

Tell the child:
-- Is it easier to add 17 + 24 or 10 + 20? Why?
-- That's right, it's easy to add numbers that end with 0!
-- So we're always going to try to group numbers that make a 10.
-- Do you see any ways to make 10 in our problem?
-- 7 + 3 = 10
-- So now, let's rewrite our problem to make it easier to solve
-- I'm writing 90 + 90 + 10 [Write]
-- We took out the 7 and 3, and made a ten. [Point to the numbers as you say this]
-- Now, do you see any ways to make 100? [You may remind students that 100 is also "a ten"]
- That's right! We can add the 90 + 10 first, because we know that equals 100.
[Note: It's ok if the child wants to add 90 + 90 first! Whatever method is fastest for them]
- Now let's rewrite our problem again to make it easier to solve
- I'm writing 90 + 100
- Wow, it's so easy to add a number to 100! What's the answer?
- 190

Here are some other problems that you can practice with. Remember, it will be slow at first, and it's okay to use physical models.

12 + 48
33 + 67
55 + 15
81 + 49

Yes there's a lot of prior knowledge that goes into this! If this hits 2000 likes I'll make videos on those mini lessons.