This Maths article explains both the mental method and written method for multiplying a 2-digit number by a 1-digit number.

In National 4 Maths multiply a number given to two decimal places by a single-digit whole number and by multiples of 10, 100 and 1000.

We'll explore how this shortcut works for both two-digit numbers multiplied by themselves, and even for multiplying two different numbers ending in 5.

Most everyone learns to multiply the same way. We stack two numbers, multiply every digit in the bottom number by every digit in the top number, and do addition at the end.