Missing Factors: Find the Unknown Number
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Skill: Finding the unknown number in multiplication and division equations
10 versions, each with its own answer key
Same skill and layout, a fresh set of problems in every version, so children can keep practicing without repeating a page. Problems are not repeated between versions unless a skill has only a small number of possible problems (for example, the addition facts within 10).
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About this worksheet
A missing factor problem hides one number in a multiplication or division fact, such as 6 × ___ = 42. Solving it means thinking about how multiplication and division are connected, which is a key third-grade idea. This third-grade worksheet gives twenty equations with one number missing. Students find the unknown number and write it in the blank.
The problems come in four kinds, with five of each, mixed together: the first factor is missing (___ × 7 = 56), the second factor is missing (4 × ___ = 36), the number being divided is missing (___ ÷ 3 = 9), or the divisor is missing (45 ÷ ___ = 5). All factors are from 2 to 10, so every answer comes from a fact students already know. The ten versions never repeat a problem.
How to use it: read each equation as a question. For 6 × ___ = 42, ask, "Six times what makes 42?" For a division problem, turn it into multiplication: ___ ÷ 3 = 9 asks which number makes 9 groups of 3. Encourage students to check each answer by putting it in the blank and reading the whole fact out loud. A multiplication chart is a good support at first.
The answer key shows every equation with the missing number filled in. This worksheet supports Common Core standards 3.OA.A.4 (determine the unknown whole number in a multiplication or division equation) and 3.OA.B.6 (understand division as an unknown-factor problem). Review our Multiplication Facts 6-9 and Division Facts 6-9 worksheets first.