Page 51 - NUMINO TG_6A
P. 51
Activity 1 Adding and Subtracting Fractions
jOb ective Practice adding and subtracting fractions.
1. Textbook Instructions Activity 1 Adding and Subtracting Fractions
Explain to students how to add fractions using Learn how to add and subtract fractions.
the least common denominator.
3 + 5
Add. 4 6
Example: Add 3 5 . 3 5 = 3\3 5\2 Write equivalent
4 6 4 6 4\3 6\2 fractions using the
+ +
least common
The least common multiple of 4 and 6 is 12, 9 10 19 7 denominator. Add
12 12 12 12
as 4 3 12 and 6 2 12. = + = = 1 or subtract the
fractions. Then
Multiply each fraction by appropriate fraction 71 write the answer in
Subtract. 12 4 simplest form.
that equals 1 so that the fractions have the 7 1 7\1 1\3
12 4 12\1 4\3
same denominator, so 3 3 9 =
4 3 12
5 2 10
and 6 2 12 . = 7 3 = 4 = 1
12 12 12 3
9 10 19
Add 12 12 to get 12 .
Remind students to simplify 19 to 1 7 . 1 . Add or subtract. Write your answer in simplest form.
12 12
a. 1 + 1 = 5 b. 8 1 = 3
3 2 6 10 5 5
1. Have students add or subtract the fractions c. 3 + 2 1 = 5 1 d. 7 5 = 6 1
4 4 6 6
using the least common denominator following 3 2 6 3
7 3 7 5
the method above. Remind them to write all e. 3 + 1 = 5 2 f. 8 4 = 4 9
21 35
fractions greater than 1 as improper fractions. 2 . Add or subtract. Write your answer in simplest form.
For example, in 1e. the mixed number 3 3 1 5 1 1 1
7 3 6 2 4 8
24 a. + + = 1 2 b. 2 = 1 5
should be written as 7 . 3 8
2. Have students solve the remaining problems. c. 2 7 + 1 1 + 1 = 4 5 d. 1 11 1 3 = 5
8 2 4 8 12 3 4 6
20
2. Build Understanding
Have students practice finding the least common denominators with simple problems.
Example: 2 2
3 5
The least common denominator is 15, as 3 5 15 and 5 3 15.
Multiply each fraction by the appropriate fraction that equals 1, so ( 2 5 ) ( 2 3 ) 10 6 .
3 5 5 3 15 15
10 6 16
Add the two fractions, 15 15 15 .
Simplify to 1 1 .
15
034 NUMINO Teacher s Guide
jOb ective Practice adding and subtracting fractions.
1. Textbook Instructions Activity 1 Adding and Subtracting Fractions
Explain to students how to add fractions using Learn how to add and subtract fractions.
the least common denominator.
3 + 5
Add. 4 6
Example: Add 3 5 . 3 5 = 3\3 5\2 Write equivalent
4 6 4 6 4\3 6\2 fractions using the
+ +
least common
The least common multiple of 4 and 6 is 12, 9 10 19 7 denominator. Add
12 12 12 12
as 4 3 12 and 6 2 12. = + = = 1 or subtract the
fractions. Then
Multiply each fraction by appropriate fraction 71 write the answer in
Subtract. 12 4 simplest form.
that equals 1 so that the fractions have the 7 1 7\1 1\3
12 4 12\1 4\3
same denominator, so 3 3 9 =
4 3 12
5 2 10
and 6 2 12 . = 7 3 = 4 = 1
12 12 12 3
9 10 19
Add 12 12 to get 12 .
Remind students to simplify 19 to 1 7 . 1 . Add or subtract. Write your answer in simplest form.
12 12
a. 1 + 1 = 5 b. 8 1 = 3
3 2 6 10 5 5
1. Have students add or subtract the fractions c. 3 + 2 1 = 5 1 d. 7 5 = 6 1
4 4 6 6
using the least common denominator following 3 2 6 3
7 3 7 5
the method above. Remind them to write all e. 3 + 1 = 5 2 f. 8 4 = 4 9
21 35
fractions greater than 1 as improper fractions. 2 . Add or subtract. Write your answer in simplest form.
For example, in 1e. the mixed number 3 3 1 5 1 1 1
7 3 6 2 4 8
24 a. + + = 1 2 b. 2 = 1 5
should be written as 7 . 3 8
2. Have students solve the remaining problems. c. 2 7 + 1 1 + 1 = 4 5 d. 1 11 1 3 = 5
8 2 4 8 12 3 4 6
20
2. Build Understanding
Have students practice finding the least common denominators with simple problems.
Example: 2 2
3 5
The least common denominator is 15, as 3 5 15 and 5 3 15.
Multiply each fraction by the appropriate fraction that equals 1, so ( 2 5 ) ( 2 3 ) 10 6 .
3 5 5 3 15 15
10 6 16
Add the two fractions, 15 15 15 .
Simplify to 1 1 .
15
034 NUMINO Teacher s Guide
