Number Bonds - A Magic Trick!

Here is a really quick way to calculate number bonds up to 100,000.  It is SO easy!

An example of a question would be 36 + ___ = 100.

The ones column has to add to 10.  For example:  6 + 4 = 10

The tens column (and anything higher such as hundreds), has to add to 9.  For example:  3 + 6 = 9.

So . . . 36 + 64 = 100

Credit for this awesomely quick strategy must go to the teachers at Auroa School, in Taranaki.