Japanese multiplication

The Japanese multiplication method is an easy visualization method that reduces a multiplication to counting and addition. The numbers are drawn as sets of parallel lines and arranged with spaces in between. Line intersections represent products of digits, which vertically align into columns. The number of intersections in each column can be read as numeral.

If the number of intersections exceeds 9 the first digit of a numeral is added to the second digit of the previous numeral. This simple method works because the result is obtained by adding up all products of numbers of the same power of 10.

Japanese multiplication is a visual form of the grid method, which has been standard in mathematics education in primary schools in England and Wales. Grid multiplication is considered to be more reliable as the multiplication of multi-digit numbers can be split into a number of smaller multiplications, which can then be easily added up.