Develop understanding of fractions as numbers.3
1. Understand a fraction 1/b as the quantity formed by 1 part when a whole is partitioned into b equal parts; understand a
fraction a/b as the quantity formed by a parts of size 1/b.
CST Bridge 
Decimals, Fractions and Percents
3.0 Students understand the relationship between
whole numbers, simple fractions,
and decimals:
3.11 Compare fractions represented by drawings or concrete materials to show equivalency
and to add and subtract simple fractions in context (e.g., ½ of a pizza is the same amount as 2/4 of another pizza that is the same size; show that 3/8 is larger than ¼).


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.

Use equivalent fractions as a strategy to add and subtract fractions.
1. Add and subtract fractions with unlike denominators (including mixed numbers) by replacing given fractions with equivalent
fractions in such a way as to produce an equivalent sum or difference of fractions with like denominators. For example,
2/3 + 5/4 = 8/12 + 15/12 = 23/12. (In general, a/b + c/d = (ad + bc)/bd.)
CST Bridge 
Key Standard
2.35 Solve simple problems, including ones arising in concrete situations, involving the addition and subtraction of fractions and mixed numbers (like and unlike denominators of 20 or less), and express answers in the simplest form.

