2.3 Adding in Different Ways
A very useful method to calculated addition is called *written mental calculation*. You need a paper and pencil in order to write down a *simplification* in order to do calculations in your head. There are many ways to do this, and no single way is correct. You may find your own method that works for you.
Here below are a few examples of different methods you can use for written mental calculations:
A Calculating by sorting each number by itself
44 + 39 + 52
Here we add the tens and ones each on their own!
44 + 39 + 52 = (40 + 30 + 50) + (4 + 9 + 2) = 120 + 15 = 135 |