Important update, Jan. 17 at 18:00 UTC: There have been a lot of objections raised about the video mentioned below and the way I describe the math therein. It’s more than I can simply add or update ...

In adding and subtracting fractions with unlike denominators, you have to get a least common denominator which is exactly like the least common multiple it just so happens to be in the denominator.

Fractions are the basis for most higher-level mathematics. Students need to master the numerical values in earlier grades to tackle topics like algebra later. There’s only one hitch: Fractions can ...