It's possible to solve some multiplication problems in your head. But sometimes it can help to use other methods instead. These include using visual aids, such as an array or place counters, or by ...

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 ...

After duplex numbers, let us learn multiplication by triplex numbers. As the name suggests, numbers like 111, 222, 333 are triplex numbers. The method is similar to that of multiplication by duplex ...

David Harvey receives funding from the Australian Research Council. Around 1956, the famous Soviet mathematician Andrey Kolmogorov conjectured that this is the best possible way to multiply two ...