# Addition - Multiple Numbers

Once students learn their additional facts, they should learn to add multiple numbers.

There are many ways to add columns of numbers. Of course, the strategies of counting up and counting on (holding a number, or sum, in your head while counting on another number) always work.

However, once students know their math facts, they can work faster than that. And, if students know the pairs that add up to nicely added-to numbers (like 10), they can work even faster.

Example:

$7+5+3=$

Students can know that 7 and 5 make 12 and another 3 makes 15.

But, because addition has the commutative properties, it doesn't matter which order the numbers are added up in. So, students can know that 7 and 3 make 10, and another 5 is 15.

Both methods work. But, finding pairs that make 10 can make addition faster.

The same methods work with multi-digit numbers, just work column by column, and don't forget to carry or regroup!

#### Practice Problems:

## Addition - Multi-Digit

Find the following sums:

- $1+9+4=$
- $2+8+7=$
- $4+9+6=$
- $1+2+7=$
- $10+9+1=$
- $10+8+4=$
- $11+9+4=$
- $13+2+6=$
- $15+6+2=$
- $19+9+2=$
- $18+6+4=$

#### Answer Key: