3rd grade Instructional Guide

Operations and Algebraic Thinking

Core Guide

Grade 3

Represent and solve problems involving multiplication and division within 100 (Standards 3.OA.1–4 and Standard 3.OA.7). Standard 3.OA.1 Interpret products of whole numbers, such as interpret 5 × 7 as the total number of objects in 5 groups of 7 objects each. For example, describe a context in which a total number of objects can be expressed as 5 × 7. Concepts and Skills to Master • Understand multiplication as combining equal groups of objects • Model skip counting on a number line • Understand that in a multiplication equation, the first factor equals the number of groups and the second factor equals the number in each group • Find the total number of objects within equal groups (5 × 7 = 35; 5 groups of 7 is 35)

• Write multiplication expressions and equations to represent pictures • Draw pictures to represent multiplication expressions and equations Related Standards: Current Grade Level

Related Standards: Future Grade Levels 4.OA.1, 4.OA.2 Interpret and solve a multiplication equation as a comparison 4.NBT.5 Multiply multi-digit whole numbers 5.NBT.5 Fluently multiply multi-digit whole numbers 4.NF.4, 5.NF.4 Apply and extend

3.OA.2 Interpret whole-number quotients of whole numbers 3.OA.3 Use multiplication and division to solve word problems involving equal groups, arrays, and measurement quantities 3.OA.4 Determine the unknown whole number in a multiplication or division equation relating three whole numbers. 3.OA.5 Apply properties of operations as strategies to multiply and divide 3.OA.6 Understand both division as an unknown-factor problem and the relationship between multiplication and division 3.OA.7 Fluently multiply and divide within 100

previous understandings of multiplication to fractions

Critical Background Knowledge from Previous Grade Levels • Use addition to find the total number of objects in an array (2.OA.4) • Skip count by fives and tens (2.NBT.2) Academic Vocabulary equal groups, array, multiplication, factor, product, equation Suggested Models

Suggested Strategies • Model equal groups with various counters • Discuss real-life situations where objects are in groups • Use and compare number lines, bar models, and area models

Write an equation that can help you find the total number of points on the stars. 3 × 5 = 15

Frank bought six boxes of crayons. Each box of crayons has 8 crayons in it. How many crayons does he have?

3.OA.1