Addition by subtraction is a curious phenomenon. It occurs in politics — for a timely example — when a reduced field of candidates helps voters and media focus more attention on those who remain. It ...

You can add or subtract numbers in lots of different ways. You can use number lines, number bonds, fact families, 10 squares and counters, or even just writing the numbers down. Sometimes it is faster ...

Here you will find a video about addition and subtraction. Watch this, and then test your knowledge with a short quiz before exploring the rest of the collection. This section contains videos from our ...

Ever dreamt of solving math problems in your head with the speed of a calculator? Mental math might seem challenging, but it's a skill attainable through the right tools and techniques. The abacus, an ...

A thorough understanding of addition and subtraction requires knowledge of the inverse relation between these operations. According to Piaget (1952), any inverse relation poses a significant challenge ...