Several number cards are laid out in front of you.
At the end of the row is the card with the target number.
Find two cards that together make exactly the target number.
Example: The target number is 8.
The cards 5 and 3 fit, because 5 + 3 = 8.
The filled in example shows the answer.
Example
For parents
What does this exercise practice?
Deliberately searching for matching addends trains flexible decomposition of numbers and mental math.
Common pitfalls
Children often try out all pairs at random. It is faster to pick one card and think about which second number is still missing to reach the target.
How to practice at home
Name a target number with playing cards and search together for two matching cards. It gets trickier with bigger numbers.
Related: Splitting Numbers, Number Sentences with a Gap