Column addition is a way of adding numbers together. It's helpful when you're adding two-digit or three-digit numbers together. When you do column addition, you lay out the numbers you are adding ...

Subtracting larger numbers in your head is not always easy, so you can use the column method to take one number away from another. You write the larger number above the smaller number, so that the ...

Ever wanted to impress everyone by solving complex multiplication problems in your head, without needing a pencil or paper? It's not magic; it's mental math—a superpower you can learn! This article is ...

Karen C. Fuson, Diana Wearne, James C. Hiebert, Hanlie G. Murray, Pieter G. Human, Alwyn I. Olivier, Thomas P. Carpenter and Elizabeth Fennema Researchers from 4 projects with a problem-solving ...