Hi welcome to my Maths of Place Value and Tidy numbers.
Place Value is useful for addition and subtraction, For Example:
235+541=776
200+500=700
30+40=70
5+1=6
Tidy Number uses addition and subtraction as well as Place Value so here is an example for a tidy number:
32 + 56 =
-1 +1
31 + 57 = 88
