Fractions: Grades 3-5. Equivalency, Addition, and Subtraction Druid Hills Elementary. CCSS.Math.Content.3.NF.A.3 Explain equivalence of fractions in special cases, and compare fractions by reasoning about their size.
Equivalency, Addition, and Subtraction
Druid Hills Elementary
CCSS.Math.Content.3.NF.A.3 Explain equivalence of fractions in special cases, and compare fractions by reasoning about their size.
Grade 3 expectations in this domain are limited to fractions with denominators 2, 3, 4, 6, 8.
Know that adding and subtraction of fractions is the putting together and taking apart of same sized pieces from the same whole.
Use what you know about equivalency or decomposing numbers to add and subtract fractions.
CCSS.Math.Content.4.NF.B.3d Solve word problems involving addition and subtraction of fractions referring to the same whole and having like denominators, e.g., by using visual fraction models and equations to represent the problem.
Grade 4 expectations in this domain are limited to fractions with denominators 2, 3, 4, 5, 6, 8, 10, 12.
As students make the cards, what do you need to do to ensure they are engaging in
4.NF.2. Compare two fractions with different numerators and different denominators, e.g., by creating common denominators or numerators, or by comparing to a benchmark fraction such as 1/2. Recognize that comparisons are valid only when the two fractions refer to the same whole. Record the results of comparisons with symbols >, =, or <, and justify the conclusions, e.g., by using a visual fraction model.
4.NF.1. Explain why a fraction a/b is equivalent to a fraction (n × a)/(n × b) by using visual fraction models, with attention to how the number and size of the parts differ even though the two fractions themselves are the same size. Use this principle to recognize and generate equivalent fractions.
How could students prove whether the following equation is true or false?
+ + + = 1
But I thought students didn’t have to add with unlike denominators! Read teacher note p. 56