Missing addend - Rectangle

Sum up to

Theme

🍫 Eat chocolate-bar together!

Imagine the rectangle was a chocolate-bar you and mom shared.

Can you figure out how many pieces Mom ate?

There are 1 pieces.

You ate 1 pieces.

1+00=1

There are 19 pieces.

You ate 12 pieces.

12+00=19

There are 8 pieces.

You ate 3 pieces.

3+00=8

There are 15 pieces.

You ate 9 pieces.

9+00=15

There are 13 pieces.

You ate 5 pieces.

5+00=13

There are 1 pieces.

You ate 1 pieces.

1+00=1

There are 7 pieces.

You ate 5 pieces.

5+00=7

There are 15 pieces.

You ate 15 pieces.

15+00=15

There are 18 pieces.

You ate 7 pieces.

7+00=18

There are 16 pieces.

You ate 11 pieces.

11+00=16

There are 7 pieces.

You ate 7 pieces.

7+00=7

There are 11 pieces.

You ate 10 pieces.

10+00=11

There are 9 pieces.

You ate 5 pieces.

5+00=9

There are 11 pieces.

You ate 5 pieces.

5+00=11

There are 19 pieces.

You ate 13 pieces.

13+00=19

What is this?

[Rectangle version] "Missing Addend" is a fun and interactive math activity for kids. Given one addend and the sum, kids will figure out the other addend. A great way to build addition skills and number sense!

Hints:

Help kids understand the relationship between rectangles and numbers.
Then from the relationship to math addition.
Let kids write the math equation down!
Have fun! Keep kids busy!