Lesson 7

Using Diagrams to Represent Multiplication

Problem 1

Here is a rectangle that has been partitioned into four smaller rectangles.

Rectangle divided into 4 smaller rectangles labeled A, B, C, D. Length across top is 3.4 and width is 2.6.

For each expression, choose the sub-rectangle whose area, in square units, matches the expression.

  1. \(3 \boldcdot (0.6)\)
  2. \((0.4) \boldcdot 2\)
  3. \((0.4) \boldcdot (0.6)\)
  4. \(3 \boldcdot 2\)

Solution

For access, consult one of our IM Certified Partners.

Problem 2

Here is an area diagram that represents \((3.1) \boldcdot (1.4)\).

Large rectangle divided into rectangles A and B. Length across top of rectangle A is 3 point 1. Width of rectangle A is 1. Width of rectangle B is 0 point 4.
  1. Find the areas of sub-rectangles A and B.
  2. What is the area of the 3.1 by 1.4 rectangle?

Solution

For access, consult one of our IM Certified Partners.

Problem 3

Draw an area diagram to find \((0.36) \boldcdot (0.53)\). Label and organize your work so that it can be followed by others.

Solution

For access, consult one of our IM Certified Partners.

Problem 4

Find each product. Show your reasoning.

  1. \((2.5) \boldcdot (1.4)\)
  2. \((0.64) \boldcdot (0.81)\)

Solution

For access, consult one of our IM Certified Partners.

Problem 5

Complete the calculations so that each shows the correct sum.

Four calculations with missing digits. 

Solution

For access, consult one of our IM Certified Partners.

(From Unit 5, Lesson 3.)

Problem 6

Diego bought 12 mini muffins for $4.20.

  1. At this rate, how much would Diego pay for 4 mini muffins?
  2. How many mini muffins could Diego buy with $3.00? Explain or show your reasoning. If you get stuck, consider using the table.
number of
mini muffins
price in
dollars
12 4.20

Solution

For access, consult one of our IM Certified Partners.

(From Unit 2, Lesson 12.)