3-5 dividing decimals by whole numbers homework presentation homework presentation
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3-5 Dividing Decimals by Whole Numbers
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3-5 Dividing Decimals by Whole Numbers
Learn to divide decimals by whole numbers.
3-5 Dividing Decimals by Whole Numbers
Divisor
Quotient
Remember!
0.150.755
Dividend
3-5 Dividing Decimals by Whole Numbers
Additional Example 1A: Dividing a Decimal by a Whole Number
Find the quotient.
0.84 ÷ 3
3 0.84
– 624
– 240
Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers.
0.28
3-5 Dividing Decimals by Whole Numbers
Additional Example 1B: Dividing a Decimal by a Whole Number
Find the quotient.
3.56 ÷ 4
4 3.56
– 3236
– 360
Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers.
0.89
3-5 Dividing Decimals by Whole Numbers
Check It Out: Example 1A
Find the quotient.
0.72 ÷ 3
3 0.72
– 612
– 120
Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers.
0.24
3-5 Dividing Decimals by Whole Numbers
Check It Out: Example 1B
Find the quotient.
2.96 ÷ 4
4 2.96
– 2816
– 160
Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers.
0.74
3-5 Dividing Decimals by Whole Numbers
Additional Example 2A: Evaluating Decimal Expressions
Evaluate 0.936 ÷ x for the given value of x.
x = 9
9 0.936– 9
3– 0
36
Substitute 9 for x. 0.10
0.936 ÷ x
0.936 ÷ 9
– 360
4Sometimes you need to use a zero as a placeholder.
9 > 3, so place a zero in the quotient and divide 9 into 36.
3-5 Dividing Decimals by Whole Numbers
Additional Example 2B: Evaluating Decimal Expressions
Evaluate 0.936 ÷ x for the given value of x.
x = 18
18 0.936– 0
93– 90
36
Substitute 18 for x. 0.05
0.936 ÷ x
0.936 ÷ 18
– 360
2Sometimes you need to use a zero as a placeholder.
18 > 9, so place a zero in the quotient and divide 18 into 93.
3-5 Dividing Decimals by Whole Numbers
Check It Out: Example 2A
Evaluate 0.636 ÷ x for the given value of x.
x = 6
6 0.636– 6
3– 0
36
Substitute 6 for x. 0.10
0.636 ÷ x
0.636 ÷ 6
– 360
6Sometimes you need to use a zero as a placeholder.
6 > 3, so place a zero in the quotient and divide 6 into 36.
3-5 Dividing Decimals by Whole Numbers
Check It Out: Example 2B
Evaluate 0.636 ÷ x for the given value of x.
x = 12
12 0.636– 0
63– 60
36
Substitute 12 for x. 0.05
0.636 ÷ x
0.636 ÷ 12
– 360
3Sometimes you need to use a zero as a placeholder.
12 > 6, so place a zero in the quotient and divide 12 into 63.
3-5 Dividing Decimals by Whole Numbers
Multiplication can “undo” division. To check your answer to a division problem, multiply the divisor by the quotient.
Remember!
3-5 Dividing Decimals by Whole Numbers
Additional Example 3: Consumer Application Jodi and three of her friends are making a tile design. The materials cost $10.12. If they share the cost equally, how much should each person pay?
4 $10.12– 8
21– 20
12
$2.53
$10.12 should be divided into four equal groups.
Divide $10.12 by 4.
– 120
Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers.
Check2.53 4 = 10.12Each person should pay $2.53.
3-5 Dividing Decimals by Whole Numbers
Check It Out: Example 3
Ty and three of his friends are building a fence. The lumber costs $21.44. If they share the cost equally, how much should each person pay?
4 $21.44– 20
14– 12
24
$5.36
$21.44 should be divided into four equal groups.
Divide $21.44 by 4.
– 240
Place a decimal point in the quotient directly above the decimal point in the dividend. Divide as you would with whole numbers.
Check5.36 4 = 21.44Each person should pay $5.36.
3-5 Dividing Decimals by Whole Numbers
Check For Understanding
Find each quotient.
1. 3.12 ÷ 8 2. 5.68 ÷ 8
Evaluate the expression 1.25 ÷ x for the given
value of x.
3. x = 5 4. x = 25
5. The tennis team is having 3 of their tennis
rackets restrung. The total cost is $54.75. What is
the average cost per racket?