A number tree shows how a number breaks apart into smaller and smaller pieces.
The number at the top splits into two branches, and each branch splits again into two leaves.
Example: 70 = 40 + 30.
The 40 branch splits into 25 and 15, the 30 branch splits into 12 and 18.
Tip: two numbers on one branch always add up to the number above them.
The numbers filled in show the solution.
Example
For parents
What does this exercise practice?
Break numbers up to 100 apart in several steps and see how parts and whole belong together.
Common pitfalls
Children often mix up which number is the sum and which are the parts. On the tree the rule helps: the number higher up is always the sum of the two numbers below it.
How to practice at home
Name a two-digit number and draw a tree together on paper: first split it into two, then into four parts.
Related: Splitting Numbers, Number House