The 2,300-year-old matrix is the world's oldest decimal multiplication table. From a few fragments out of a collection of 23-century-old bamboo strips, historians have pieced together what they say is ...

Q: How much is 230 times 10? A: The number of years humans have been calculating with decimals. A crack team of scholars in Beijing learned this last year when they solved a 23-centuries-old puzzle.

Practise your 2 times tables with this quiz. The 5 times table Learn all about the 5 times table and find out about multiples of 5. The 10 times table Discover the 10 times tables and try this quiz.

Using arrays to find the factors of whole numbers between 10 and 100. Identifying the factors of composite numbers and prime numbers. Using multiplication and division facts to visualise and plan ...

THESE tables aim at popularising logarithms. Like other four-figure tables they give the logarithms of numbers from 1000 to 9999. While the ordinary tables give these in one opening of two pages by ...