In the era of calculators, I'll admit it, it might take me a few seconds to adjust to doing mental calculations. (k9magazine.com)
It was made for a bottom set year 8 who are struggling with basic mental calculations and also finding and discussing strategies for solving problems. (tes.com)
The more comfortable we get, the more we start to make mental calculations about situations, like being in a job we hate or in a relationship that has run its course. (inc.com)