## Thursday, July 25, 2013

### Multiplying Fractions, Part I

We've pulled together some activities and worksheets to help your students learn to multiply fractions. Let's start with multiplying whole numbers and fractions using number lines, repeated addition and area models. Giving your students lots of practice will help get these concepts into long-term memory.

In Excel Math, students learn to add and subtract fractions, multiply and divide fractions, and solve word problems involving decimals and fractions. The unique spiraling system built into Excel Math lessons helps children become confident math students.

Many former Excel Math students mention that they first began to develop a love for math during their elementary school years. With Excel Math lessons, students learn practical ways to apply mathematical concepts to their everyday lives.

Preparation: Draw a number line on the board with a range of 0 - 2, showing increments of 1/5:

If you have room, create a life-size number line on the floor or wall of your room using colored tape.

Give each student a Fraction Pieces page and scissors. Download the Fraction Pieces file here.

Write some multiplication problems on the board:
4 x 1/2 =
3 x 2/5 =
8 x 2/3 =
5 x 4/6 =
2 x 3/12 =

Do the first problem together. Show the students how they can use their fraction pieces and repeated addition to calculate the answers:
4 x 1/2  =  1/2 + 1/2 + 1/2 + 1/2

Have a student write the process and the solution on the board. (The students do not need to simplify their answers, unless you want them to do that extra step.)

Do the second problem together. Have the students use their fraction pieces once again.
Point out that 3 x 2/5 = 6 x 1/5
Remind your students that multiplication can be thought of as repeated addition:

Have a student stand on your floor number line (or point to the wall line) and jump from 0 to 2/5, then to 4/5 and finally to 6/5 as your students say the red fractions together.

Let your students use their fraction pieces and repeated addition to solve the remaining problems. Have them represent the problems on a number line and with visual models. Talk about the different ways to find answers to these problems.
You may want to suggest that your students replace the “x” in a multiplication problem with the word “of”:
1/2 times 6, and
1/2 of 6

all mean the same thing.

If your students seem to catch on to this concept, try a word problem with fractions:
In a relay race, each runner runs 1/2 of a mile. If there are 6 team members how many miles long is the race? (3 miles)

Have your students use a number line and a visual fraction model to solve the word problem. If you have time, let them make up a fraction word problem of their own.

What techniques do you use to help students multiply fractions and whole numbers? Share your suggestions by clicking on the word "comments" below.