Try this ancient multiplication trick—halves and doubles, also called Egyptian or Russian math—where you repeatedly halve one ...

Converting between fractions, decimals and percentages is a useful problem-solving skill. The data can be more easily ordered by size when written in the same format. Calculations often give a decimal ...

Explore zero-one integer programming, a key method in logical problem-solving, using binary choices for optimal decisions in finance, production, and more.

19 is only 1 away from 20, so you prefer to start by multiplying 20 times 5, which equals 100. Then we need to take away a squadron of 5, because there are actually only 19 squadrons, not 20. 100 take ...