In every task a number is missing. It hides in the empty box.
Sometimes the answer is missing, sometimes one of the two numbers.
Example: 410 + 60 = box, so 470.
Example: box - 40 = 530. Work backwards: 530 + 40 = 570.
The numbers filled in show the solution.
Example
410+60=470
570−40=530
For parents
What does this exercise practice?
Solve addition and subtraction problems up to 1000 fluently, even when the gap is in different places.
Common pitfalls
When the gap is at the front, many children just start calculating blindly. A helpful question is: which calculation leads back to the given number?
How to practice at home
Make up a problem with a gap, for example 250 plus how much equals 600?
Related: Inverse, Number house, Table