Equivalent Fractions: Find the Missing Number
Skill: Finding equivalent fractions by multiplying numerator and denominator
Download PDF worksheetAnswer key (PDF)
Free for personal and classroom use. Print at 100% / "Actual size" on US Letter paper.
About this worksheet
Equivalent fractions name the same amount using different numbers, like 1/2 and 4/8. This fourth-grade worksheet gives 18 problems where students find the missing numerator or denominator to make two fractions equal. All denominators are the ones emphasized in grade 4: 2, 3, 4, 5, 6, 8, 10, 12, and 100.
How to use it: the key idea is that multiplying the numerator and the denominator by the same number does not change a fraction's value, because it is the same as multiplying by 1 (such as 3/3). For 2/5 = ?/10, ask, "What did 5 get multiplied by to make 10?" The answer is 2, so multiply the numerator by 2 as well: 2/5 = 4/10. When the missing number is the denominator, work the same way using the numerators. Fraction strips, folded paper, or drawing the same-sized bar divided into different numbers of parts can help students see why the fractions are equal.
The answer key gives every missing number. Students can check an answer by cross-multiplying or by simplifying the second fraction back to the first. Problems with a denominator of 100 also connect to decimals and percents, which students will see later. This worksheet supports Common Core standard 4.NF.A.1 (explain why a fraction a/b is equivalent to a fraction (n × a)/(n × b) and use this principle to recognize and generate equivalent fractions).
Count and Trace Numbers 1-10
Addition Within 10
Subtraction Within 10