Numberphile revived an ancient multiplication trick—halves and doubles—also called Egyptian or Russian math, where you repeatedly halve one number and double the other. After crossing out rows with ...

Adam Hayes, Ph.D., CFA, is a financial writer with 15+ years Wall Street experience as a derivatives trader. Besides his extensive derivative trading expertise, Adam is an expert in economics and ...

Gordon Scott has been an active investor and technical analyst or 20+ years. He is a Chartered Market Technician (CMT). Gordon Scott has been an active investor and technical analyst or 20+ years. He ...

When multiplying fractions, multiply the top numbers (numerators) together and multiply the bottom numbers (denominators) together, then simplify or it is sometimes easier simplify first.

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 ...

So many productivity methods ask you to prioritize your daily tasks by considering how much time or effort they'll require, then tackling the resource-heavy ones first. For some people, that's a solid ...