The + means: add them up. With 3 + 1 you put 3 and 1 together, that makes 4.
Find the missing number.
The gap can be anywhere!
Example: 3 + _ = 8 means the missing number is 5.
The filled in numbers show the answer.
Example
3+5=8
5+3=8
5+4=9
For parents
What does this exercise practice?
This exercise trains calculating with unknowns and strengthens the understanding that an equation must add up to the same amount on both sides.
Common pitfalls
Children often overlook where the gap is. When the gap is at the beginning, it helps to read the problem out loud: which number plus 2 makes 8?
How to practice at home
Pose little riddles in everyday life: I bought 3 apples, now there are 7, how many were already there before? This makes mental math with gaps tangible.
Related: Calculating with Pictures, Swap Problems