Page 207 - NUMINO TG_5A

070_G5U13_G6U15_TG 2014.4.18 3:34 PM ˘ ` 190

Activity 1 Dividing Whole Numbers by Fractions

jOb ective Divide whole numbers by fractions using models and reciprocals.

1. Textbook Instructions Activity 1 Dividing Whole Numbers by Fractions

This activity will familiarize students with two Student will learn to divide whole numbers by fraction. Use the drawings to help them visualize what each

pLreobalermn whoouwld ltoookdliikvei.dTehean hwavheothleemncuomunbt teher tbotyalanufmrabecrtoiof dni.vided parts to find the answer.

methods of dividing whole numbers by Method 1 Use multiplication.

fractions. 1
3
Method 1: Use models Divide. 2

Example: 2 1 Use two 1 bars to make 2. Two 1 bars six 1 bars.
3 3
1
Use two bars to make 2. Count the number of 3 bars 1
3
used to make 2. Therefore, 2 is equal to 6.

Count how many 1 bars are used to 11 11
3
make two. There are 6 bars.
1_ 1_ 1_ 1_ 1_ 1_ 1_
Express this in numerical form. 3 333333

2 1 6 1 . Divide a whole number by a fraction using the models.
3

a. 2 18 b. 1 1 6
4 6

1. Have students use models to divide whole 1 11
numbers by fractions.
1 1
4 6

c. 2 1 4 d. 3 1 9
2 3

12 34 12 45
3 6

78
9

116

2. Build Understanding

When dealing with whole numbers and fractions, students may make the mistake of dividing the whole

number by only a single part of the fraction.

Example: 2 1 2 3 0.66
3

This is incorrect. The student ignored the 1 and divided the whole number by the denominator of the

fraction. Encourage students to use models, particularly in early problems, to avoid these mistakes.

190 NUMINO Teacher s Guide