The crisp new dollar bill that I have just taken from my wallet bears the serial number 24598176. It’s easy to tell that the number is exactly divisible by 2 but not by 5. Is it divisible by 3? by 4?

Randomly scramble the digits 0, 1, 2, 3, 4, 5 and 6 to form a seven-digit number (or a six-digit number if the leading digit is 0). Rank the following events in order ...

An introduction to odd and even numbers. Even numbers are divisible by two whereas odd numbers are not. At ‘Number School’, numbers are separated into two lines - odd and even. The teacher checks ...