Mississippi Math 3.NF.3a

Math3rd GradeNumber and Operations—Fractions5 (NF) Develop Understanding of Fractions as Numbers

The Standard

3.NF.3: Explain equivalence of fractions in special cases, and compare fractions by reasoning about their size.

Understand two fractions as equivalent (equal) if they are the same size, or the same point on a number line. Recognize that comparisons are valid only when the two fractions refer to the same whole.

2025 Mississippi College- and Career-Readiness Standards for Mathematics · Solve problems Involving the Four Operations, and Identify and Explain Patterns in Arithmetic

Teacher's field guide

What This Standard Means

What Students Need to Do: Students use fraction strips or a number line to show when two fractions name the same amount. Before comparing shaded parts, they check that the wholes are the same size.
What Mastery Looks Like: A student shows that 1/2 and 2/4 cover the same length on equal-size strips and land at the same point on a number line. They notice that half of a small sheet is less paper than half of a large sheet.
Common Misconceptions: Students may think fractions with different numbers cannot be equal. They may compare shaded parts without noticing that the wholes are different sizes.
How to Assess It: Give students a 0-to-1 number line and two rectangles of different sizes. Ask them to mark 1/2 and 2/4 on the line, then explain whether shading half of each rectangle gives equal amounts of paper.

Lesson moves

Ways to Teach It

Fold two equal-length paper strips into halves and fourths, then lay one half over two fourths to see if they match.
Show half an index card beside half a full sheet of paper; ask, “Are these equal amounts of paper? Why?”
Give pairs fraction cards labeled 1/2, 2/4, 3/6, 1/3, and 2/6; have them place matches on a 0-to-1 number line.
Draw two same-size pizzas, one cut into fourths and one into eighths; compare two fourths with four eighths.

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