The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » Inactive » k12.ed.math

Topic: Lesson Plan
Replies: 0  

Advanced Search

Back to Topic List Back to Topic List  
Zinaida Belikova

Posts: 1
Registered: 1/25/05
Lesson Plan
Posted: Nov 19, 2004 12:42 AM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply


This lesson applies the strategies for solving multiplication
equations to equations with a fraction as the coefficient of the

Students will learn how to use multiplication by reciprocals, to solve
multiplication equations in which the coefficient of the variable is a

California Content Standards:
1.2 Students add, subtract, multiply, and divide, rational numbers
(integers, fractions, and terminating decimals) and take positive
rational numbers to whole-number powers.

2.0 Students calculate, and solve problems involving addition,
subtraction, multiplication, and division.

3.3 Develop generalizations of the results obtained and the
strategies used and apply them to new problem situations.

Warm-Up Activity:
Ask students what the word reciprocal means. (If the product of two
numbers is 1, then each factor is the reciprocal of the other).

Ask students to identify the reciprocals of the following numbers:
1/4, 3/5, 7/8 and 1/n

Encourage students to describe what they know about the product of
these numbers and their reciprocals (the product equals 1).

Direct instructions for all students:
Write the first example , 1/4h = 6 on the overhead projector. Ask
students how they can change the coefficient of h from 1/4 to 1. Lead
students to conclude that multiplying the left side of the equation by
4 will give h a coefficient of 1.

Remind students that to keep the equation true, they will need to
multiply the right side of the equation by 4/1 as well.

Solve the example, showing each of the steps indicated.
1/4h = 6

(4/1)1/4 • h = 6/1 (4/1)
(4/1)1/4 • h = 6/1 (4/1)
4/4 h = 24/1
h = 24

Solve the second example showing each of the steps indicated:
-2/5x = -20
(-5/2)(-2/5) • x = -20(-5/2)
(10/10) •x = 100/2
x = 50

Working in small groups:
Divide class into small groups. Students will work in pairs by
helping each other, developing strategies and sharing the answers (in
each pair one student must have good math skills).

Group Problem Solving:
Have small groups of students consider the following situation.

Havermill School needs to increase its students’ reading and math
scores. Currently 1/7 of the school, 30 students, score above average
in reading and math. By the end of the year, the school would like
1/5 of its students to score above average. If the school meets its
goal, how many students will score above average?

(1/7)x = 30
(7/1) • 1/7 = 30(7/1)
(7/7) • x = 210/2
x = 210
(1/5) • 210 = 42

Homework assignment attached.

submissions: post to k12.ed.math or e-mail to
private e-mail to the k12.ed.math moderator:
newsgroup website: <a href=""></a>
newsgroup charter: <a href=""></a>

Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2017. All Rights Reserved.