[Decimal ×,÷]
8.
Skill 8.1
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continues on page 34
Multiply from right to left, disregarding the decimal point.
Count the number of places to the right of the decimal point in the question.
Position the decimal point the same number of places from the right in the answer.
Q. 0.62 × 4 =
A. 0.62 × 4 = 2.48
2
0.6 2
×
4
2.4 8
a)
MMBlue 1 1 2 2 3 3 4 4
MMGreen 1 1 2 2 3 3 4 4
Multiplying a whole number by a decimal number (1).
0.9 × 3 =
2.7
b) 0.8 × 2 =
2
0 . 9
×
3
4×2=8
4 × 6 = 24
4 × 0 + carry 2 = 2
write 8
carry 2, write 4
write 2
2 decimal places in question so
move decimal point 2 places from right in the answer
c)
0 . 8
×
2
0.7 × 5 =
0 . 7
×
5
2.7
d) 0.4 × 6 =
e)
0 . 4
×
6
g) 5.1 × 3 =
3.8 × 2 =
3 . 8
×
2
page 33
f)
0 . 3
×
7
h) 4.3 × 6 =
5 . 1
×
3
j)
0.3 × 7 =
0 . 6
×
9
i)
4 . 3
×
6
k)
1.9 × 5 =
1 . 9
×
5
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0.6 × 9 =
2.7 × 4 =
2 . 7
×
4
l)
7.3 × 8 =
7 . 3
×
8
© Math’s Mate Blue/Green Skill Builder 8
continued from page 33
Skill 8.1
MMBlue 1 1 2 2 3 3 4 4
MMGreen 1 1 2 2 3 3 4 4
Multiplying a whole number by a decimal number (2).
m) 0.24 × 5 =
1
n) 0.71 × 6 =
2
0 . 2 4
×
5
o) 1.56 × 8 =
0 . 7 1
×
6
1 . 5 6
×
8
1.2 0
p) 2.09 × 4 =
q) 3.26 × 3 =
2 . 0 9
×
4
s)
14.02 × 6 =
8 × 10.91 =
t)
5 × 3.105 =
×
page 34
4 × 20.15 =
4 . 8 2
×
2
u) 18.02 × 3 =
2 0 . 1 5
×
4
w) 2.008 × 7 =
×
y)
4.82 × 2 =
3 . 2 6
×
3
1 4 . 0 2
×
6
v)
r)
×
z)
×
x)
6 × 0.521 =
×
5.312 × 4 =
×
zz) 3 × 2.041 =
×
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© Math’s Mate Blue/Green Skill Builder 8
Skill 8.2
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Line up the decimal point in your answer with the decimal point in the question.
Divide from left to right.
Break down the division into smaller divisions.
If any result is less than 1: Cross off the number being divided into.
‘Carry over’ this amount to the next column.
Add on the carry.
Then try dividing again.
Always keep your working columns in line, aligning units with units, tens with tens, etc.
Q. 1.26 ÷ 9 =
A. 1.26 ÷ 9 = 0.14
0 . 14
1 3
9 1 . 26
a)
MMBlue 1 1 2 2 3 3 4 4
MMGreen 1 1 2 2 3 3 4 4
Dividing a decimal number by a whole number.
4.2 ÷ 6 =
0.7
b) 2.4 ÷ 8 =
1 ÷ 9 = ? (less than 0) carry 1, write 0
Line up the decimal point.
12 ÷ 9 = 1
carry 3, write 1
36 ÷ 9 = 4
write 4
c)
1.5 ÷ 3 =
÷ from left
0.7
4
6 4 . 2
8 2 . 4
3 1 . 5
Line up decimal points
d) 6.5 ÷ 5 =
e)
.
5 6 . 5
g) 15.3 ÷ 9 =
2.66 ÷ 7 =
7
m) 10.4 ÷ 4 =
page 35
f)
4 7 . 2
h) 1.11 ÷ 3 =
k)
0.96 ÷ 6 =
6
9.8 ÷ 7 =
7 9 . 8
i)
3 1 . 1 1
9 1 5 . 3
j)
7.2 ÷ 4 =
14.5 ÷ 5 =
5 1 4 . 5
l)
2.72 ÷ 8 =
8
n) 1.47 ÷ 3 =
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o) 23.4 ÷ 9 =
© Math’s Mate Blue/Green Skill Builder 8
Skill 8.3
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•
Multiply from right to left, disregarding the decimal point.
Count the number of places to the right of the decimal point in the question.
Position the decimal point the same number of decimal places from the right in the answer.
Use zeros as place holders, if necessary.
Example: 0.02 × 0.3 = 0.006
If the result is less than 1, write a zero in the units place.
Example: By convention 0.37 not .37
Q. 2.5 × 0.8 =
A. 2.5 × 0.8 = 2
4
2.5
× 0.8
2.0 0
a)
MMBlue 1 1 2 2 3 3 4 4
MMGreen 1 1 2 2 3 3 4 4
Multiplying a decimal number by a decimal number.
0.8 × 0.9 =
0.72
b) 0.3 × 0.4 =
7
0 . 8
× 0 . 9
8 × 5 = 40
8 × 2 + carry 4 = 20
carry 4, write 0
write 20
2 decimal places in question so
move decimal point 2 places from right in the answer
c)
0 . 3
× 0 . 4
0.5 × 0.8 =
0 . 5
× 0 . 8
0.7 2
d) 0.7 × 0.6 =
e)
0.9 × 0.4 =
0 . 7
× 0 . 6
0 . 9
× 0 . 4
g) 1.4 × 0.7 =
h) 2.3 × 0.9 =
1 . 4
× 0 . 7
2 . 3
× 0 . 9
j)
0.5 × 0.06 =
×
0.03
k)
0.5
0. 0 6
0.0 3 0
0.16 × 0.3 =
0 . 1 6
×
0 .3
f)
1.2 × 0.6 =
1 . 2
× 0 . 6
i)
1.6 × 0.3 =
1 . 6
× 0 . 3
l)
1.07 × 0.9 =
1 . 0 7
×
0 .9
remove
unnecessary zero
< 1 so write zero in units place
page 36
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© Math’s Mate Blue/Green Skill Builder 8
Skill 8.4
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•
•
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•
•
Move the decimal point to the right in the divisor, as many places as you need to make a
whole number.
Then move the decimal point the same number of places to the right in the dividend.
Example: 0.56 ÷ 0.8 = 5.6 ÷ 8 = 0.7
Add zeros as place holders, if necessary.
Example: 4.9 ÷ 0.07 = 4.90 ÷ 0.07 = 490 ÷ 7 = 70
Line up the decimal point in your answer with the decimal point in the question.
Divide from left to right.
Break down the division into smaller divisions.
If any result is less than 1: Cross off the number being divided into.
‘Carry over’ this amount to the next column.
Add on the carry.
Then try dividing again.
Always keep your working columns in line, aligning units with units, tens with tens, etc.
Q. 0.63 ÷ 0.7 =
a)
MMBlue 1 1 2 2 3 3 4 4
MMGreen 1 1 2 2 3 3 4 4
Dividing a decimal number by a decimal number.
A. 0.63 ÷ 0.7 =
= 6.3 ÷ 7
= 0.9
3.6 ÷ 0.6 =
1 place right makes a whole number
= ..................................................
36 ÷ 6
=
0 .9
6
7 6 .3
b) 1.4 ÷ 0.7 =
6
6 ÷ 7 = ? (less than 0) carry 6, write 0
Line up the decimal point.
63 ÷ 7 = 9
write 9
c)
= ..................................................
=
4.5 ÷ 0.9 =
= ..................................................
=
6
3
3 3 6
d) 7.6 ÷ 0.2 =
7
e)
= ..................................................
=
6.9 ÷ 0.3 =
f)
= ..................................................
=
0.76 ÷ 0.4 =
= ..................................................
=
4
g) 0.08 ÷ 0.4 =
h) 0.49 ÷ 0.7 =
= ..................................................
=
j)
9.5 ÷ 0.05 =
= 950
÷5
=
..................................................
i)
2.7 ÷ 0.09 =
= ..................................................
=
6.42 ÷ 0.6 =
= ..................................................
=
= ..................................................
=
k)
.
l)
7.2 ÷ 0.08 =
= ..................................................
=
5 9 5 0
page 37
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© Math’s Mate Blue/Green Skill Builder 8
Skill 8.5
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•
•
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Move the decimal point to the right in the divisor, as many places as you need to make a
whole number.
Then move the decimal point the same number of places to the right in the dividend.
Add zeros as place holders.
Example: 16 ÷ 0.4 = 16.0 ÷ 0.4 = 160 ÷ 4 = 40
Line up the decimal point in your answer with the decimal point in the question.
Divide from left to right.
Break down the division into smaller divisions.
If any result is less than 1: Cross off the number being divided into.
‘Carry over’ this amount to the next column.
Add on the carry.
Then try dividing again.
Always keep your working columns in line, aligning units with units, tens with tens, etc.
Q. 9 ÷ 0.6 =
add zero as place holder
a)
MMBlue 1 1 2 2 3 3 4 4
MMGreen 1 1 2 2 3 3 4 4
Dividing a whole number by a decimal number.
5 ÷ 0.5 =
= ..................................................
50 ÷ 5
=
A. 9.0 ÷ 0.6 =
= 90 ÷ 6
= 15
1 place right makes a whole number
1 5
3
6 9 0
b) 6 ÷ 0.3 =
10
9÷6=1
30 ÷ 6 = 5
c)
= ..................................................
=
carry 3, write 1
write 5
6 ÷ 0.4 =
= ..................................................
=
1 0
5 5 0
d) 8 ÷ 0.1 =
3
e)
= ..................................................
=
g) 9 ÷ 0.2 =
5 ÷ 0.2 =
f)
= ..................................................
=
h) 3 ÷ 0.06 =
= ..................................................
=
4 ÷ 0.5 =
= ..................................................
=
i)
7 ÷ 0.04 =
= ..................................................
=
= ..................................................
=
6
j)
2 ÷ 0.04 =
= ..................................................
=
page 38
k)
5 ÷ 0.01 =
= ..................................................
=
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l)
1 ÷ 0.25 =
= ..................................................
=
© Math’s Mate Blue/Green Skill Builder 8