cynar, 1 year ago

One of my professors, at uni, put it best. You should be able to second guess your calculator.

Also, it’s often faster to do an approximate calculation in your head, rather than getting out a calculator (or phone) and plugging the numbers in.

112 x 9.

By approximation, it’s 100ish by 10ish, so around 1000. This can often be enough. (E.g is a current below 1500mA?)

The calculator should give 1008. If it claims it is 10,080, or 12.4, you know you’ve screwed up, and should recheck your calculations. If you can’t do it in your head, then you can’t check for issues.