Lesson 4

Multiplication and Rectangles

Est. Class Sessions: 3
X

Mathematical Standards

3.OA.A
Represent and solve problems involving multiplication and division. (3.OA.A.1, 3.OA.A.2, 3.OA.A.3)
3.OA.B
Understand properties of multiplication and the relationship between multiplication and division. (3.OA.B.5)
3.OA.C
Multiply and divide within 100. (3.OA.C.7)

Standards for Mathematical Practice

MP1.
Make sense of problems and persevere in solving them.
MP2.
Reason quantitatively.
MP5.
Use appropriate tools strategically.
MP6.
Attend to precision.
MP7.
Look for and make sense of structure.

Students arrange square-inch tiles into rectangles to find factors of 6, 12, and 18. They turn the rectangles around and learn that changing the order of the factors in a multiplication sentence does not change the product (e.g., 3 × 6 = 18 and 6 × 3 = 18). Students build squares with their tiles to derive the square number multiplication facts and look for patterns among square numbers.

Content in this Lesson

  • Making connections among representions of multiplication (rectangular arrays and number sentences) [E1].
  • Deriving turn-around facts (a × b = b × a) [E4].
  • Writing number sentences for multiplication situations [E1].
  • Investigating square and prime numbers.
  • Using strategies to solve multiplication and division problems [E2].
X

Materials for Students

Daily Practice and Problems Lesson Homework Assessment

Student Books

 Student Guide
Student Activity Book

Teacher Resources

 Teacher Guide - digital

Supplies for Students

My Multiplication Table with the 0, 1, 2, 3, 5, and 10 columns completed during Lesson 3 Handy Facts (Student Activity Book) Page 216
25 square-inch tiles of one color
crayon or marker

Supplies for Each Pair of Students

clear plastic spinner or pencil and paper clip
scissors

Materials for the Teacher

Display of Square-Inch Grid Paper (Student Activity Book) Page 267
Display of Centimeter Grid Paper Master (Teacher Guide)
Display of My Multiplication Table with the 0, 1, 2, 3, 5, and 10 columns completed during Lesson 3 (Student Activity Book) Page 261
Copy of Centimeter Grid Paper Master (Teacher Guide)
Display of Spinners 1–4 and 1–10 (Student Activity Book) Page 273
Display of Floor Tiler Grid Paper (Student Activity Book) Page 275
Unit 8 Assessment Record
Math Facts Class Record
Display of the Patterns for Remembering the Facts class chart from Lesson 3
Display set of square-inch tiles

Materials Preparation

Spinners. If you do not have clear plastic spinners to place over Spinners 1–4 and 1–10, students can use paper clips and pencils. Straighten out one end of the paper clip, and place a pencil through the curved end. Then, put the point of the pencil on the center of the spinner, and spin the paper clip around the pencil, using the straightened end as the pointer. See Figure 1.

Figure 1: Using a paper clip and pencil as a spinner

Assessment in this Lesson

Assessment Expectation Assessed

Multiplication and Rectangles
Check-In: Questions 1–8
Student Guide
Page 202
E1.
Represent multiplication and division problems with number lines, drawings, rectangular arrays, and number sentences.
E2.
Use strategies to solve multiplication and division problems (e.g., skip counting, repeated addition, repeated subtraction, reasoning from known facts, and invented).
E4.
Use turn-around facts to solve multiplication problems (applying the commutative property of multiplication).

DPP Item I
Fact Families: Groups 5–6
Teacher Guide - digital
E11.
Determine the unknown number in an addition or subtraction sentence relating three whole numbers for the facts in Groups 5–8.

DPP Item K
Subtraction Facts: Groups 5–6 Again
Teacher Guide - digital
E10.
Use mental strategies to subtract for the facts in Groups 5–8.