He was so clever; he could do mental arithmetic up to fractions.

We put him to the test with a five-question mental arithmetic exam.

The adoption of this group was the first distinct step toward mental arithmetic.

Montague was not prepared for this contingency; but he did some mental arithmetic.

She thought of her eight cents, and did an example in mental arithmetic.

But while he laughed he secretly performed problems in mental arithmetic.

His brain reeled before the terrifying velocity of her mental arithmetic.

Pupils of the lower classes displayed their expertness at mental arithmetic.

How do you explain the decline in importance of the once-popular mental arithmetic?

But if--here he paused and did a short sum of mental arithmetic.

I could almost hear them doing the mental arithmetic, calculating my age backward.

Tuckham did some mental arithmetic, quaintly, with rapidly blinking eyelids and open mouth.

He did a moment's mental arithmetic, then got out his checkbook.

Alack for Pink, that a mental arithmetic problem suddenly popped into her mind!

She has nearly finished Colburn's mental arithmetic, her last work being in improper fractions.

Her turn had never before come more than twice during a mental arithmetic lesson.