This section gives you mixed practice with:
All the answers are nonnegative.
Since this is algebra, there might be some variables thrown in!
For example, you might be asked for
[beautiful math coming... please be patient]
$\,3x + 5x\,$ or
[beautiful math coming... please be patient]
$\,\frac{60t}{10}\,$.
(There's also a way to opt out of seeing any variables.)
Of course, no calculator is allowed!
The goal is to get confident and quick with these basic arithmetic facts.