Calculator - The calculator is quick but we don't have to think to solve the problem. The calculator is good for checking our work after we solve the problem a different way.

Pencil and paper - This was quick but we had to remember to regroup.

Counters - This took a long time because two-digit numbers are large. It's easy to make a mistake when counting so many objects.

Base ten blocks - The base ten blocks are faster than using counters because the blocks are already grouped by tens.

## Use Appropriate Tools Strategically

## Type of problem: Addition of two-digit numbers

Example: 23 + 41 + 19

Tools we used: