This page mixes all four operations, and each line hides one number behind a letter. This 3rd grade solving for the unknown worksheet has eight equations, labeled a to h. Two add, two subtract, three multiply and one divides. Under each equation sit four boxes with numbers, so your child solves the equation and then checks the box with the right value. A hamster rolls along in its ball on the right, and page two marks each right answer with a red tick.