Subtraction Equations

A generator of simple subtraction equations. The unknown x can be the first number, the number taken away or the answer, for example 15 – x = 9 or x – 4 = 7. Choose the range, up to 5, 10, 20, 100, 1000 or a million, and for some ranges whether the problems cross the ten. All numbers in the equation are positive.

On the website you place the equations on a worksheet and add an answer key if you like. They also go on game cards such as memory with the equation and the value of x, or into multiple-choice questions. Every time you generate, you get new equations.

It suits children from Year 2 (1st grade) as missing-number problems, with x in place of the box. Children explore how subtraction and addition are linked.