Using a Multiplication Table to Divide

In Chapter 6, students used a multiplication table to multiply. In Chapter 8, they learned about the relationship between multiplication and division. Now students will draw upon both experiences to use a multiplication table to divide. We'll begin with a quick review of how a multiplication table works.

Materials: transparency of multiplication table (use the table from the Overhead Teaching Activity for Lesson 9-1) and overhead projector for demonstration; multiplication table for each student

Preparation: Students can use the multiplication tables they made in Chapter 6 or make new tables. See page 256 in the student book for instructions or use Teaching Tool 3 in the Teacher Resource Book.

Prerequisite Skills and Background: Students should understand the concept of multiplication.

• Display a multiplication table on the overhead projector.

• Ask: Do rows go across or down?
  Students will probably know that rows go across although they may get them confused with columns. Label the left side of the table Rows.

• Ask: In what direction do columns go?
  Students should respond with up and down. Label the top of the table Columns.

• Ask: Where are factors located on the table?
  Students should identify the numbers across the top and along the left side of the table.

• Ask: Where are products located?
  Students should identify the numbers to the right of the first column and below the first row.

• On the board, write 5 6 = n.

• Ask: How can you use the multiplication table to find the product of 5 and 6?
  Some students may say to find the row for 5, the column for 6, then the square where the row and column meet. Other students may say to find the column for 5, the row for 6, and then the square where that row and column meet. Both answers are acceptable.

• Ask: What is the product of 5 and 6? (30)

• Repeat the three previous steps for more multiplication facts. Encourage students to use the correct mathematical terminology as they explain the procedure for using a multiplication table to multiply.