Mental math is a serious problem. I know that, as math teachers, we have all experienced the sinking feeling in our stomachs when we see students pull out their calculators to multiply by 10 or add 1! It makes me want to pull my hair out :)

So, I decided to challenge my class the other day. I told my Geometry Honors class that we were going to have a Mental Math Challenge. They were not allowed to use a paper, pencil, or calculator. They had to sit and listen to me give 4 directions such as…

Start with the number 5.

Add 10.

Divide by 3.

Add 2.

What is your answer?

Then they had to enter their answer immediately into a google form.

No repeating, no calculator, no pencil…it was a serious recipe for disaster!

Quite frankly, I was surprised when I graded the google forms. Students did HORRIBLE!

My students are great - the kids are good and they study…but they need help with mental math :) I figure that mental math is like exercise…you need to keep doing it to keep your mind healthy!

So, I created these task cards to help.

I think they can be used in a few ways.

1. You could use the stack of cards as a center.

2. You could read the directions on each card to the class, and then choose a student to scan the QR Code. (If you don't have a smart device to read the QR Code, no problem, an answer key is included).

3. Give a few cards to each student or group and have them trade.

4. Make the cards into a stack - punch a hole and put them on a ring. Bring them in a car for one of your children :)

4. The cards are easy to make differentiable - some are more difficult than others.

I envision creating another stack soon that also involves some negative and some larger numbers!

Let me know what you think in the comments below.