Facts with unknowns

Front

What is the unknown number? 8 + ___ = 8

Back

0

Front

What is the unknown number? 2 + ___ = 4

Back

2

Front

What is the unknown number? 10 + ___ = 10

Back

0

Front

What is the unknown number? 6 + ___ = 8

Back

2

Front

What is the unknown number? 3 + ___ = 7

Back

4

Front

What do we call a number that we don't know?

Back

Unknown number

Front

What is the result of adding 0 to any number?

Back

The same number.

Front

If you have 5 and you add ___ to get 5, what is the unknown?

Back

0

Front

What is 1 + ___ = 3?

Back

2

Front

What is 4 + ___ = 4?

Back

0