McGraw Hill Math Grade 8 Unit Test Lessons 10–12 Answer Key
Practice the questions of McGraw Hill Math Grade 8 Answer Key PDF Unit Test Lessons 10–12 to secure good marks & knowledge in the exams.
McGraw-Hill Math Grade 8 Unit Test Lessons 10–12 Answer Key
Restate in exponential form, then calculate.
Question 1.
4 × 4 × 4 + 3 × 3 × 3
Answer:
91
Explanation:
a x a x a … a(m times) = am
4 × 4 × 4 + 3 × 3 × 3
= 43 + 33
= 64 + 27
= 91
Question 2.
3 × 3 × 2 × 2 – 3 × 3 × 3
Answer:
91
Explanation:
a x a x a … a(m times) = am
3 × 3 × 2 × 2 – 3 × 3 × 3
=Â 32 x 22 – 33Â
= 9 x 4 – 27
= 36 – 27
= 9
Question 3.
4 × 4 × 4 × 2 × 2 + 4 × 4 + 6 × 6 – 3 × 3
Answer:299
Explanation:
a x a x a … a(m times) = am
4 × 4 × 4 x 2 × 2 + 4 x 4 + 6 x 6 – 3 × 3
= 43x 22 + 42 + 62 – 32Â
= 64 x 4 + 16 + 36 – 9
= 256 + 16 + 36 – 9
= 308 – 9
= 299
Restate using scientific notation.
Question 4.
13,224,714.066
Answer:
1.3224714066 x 107
Explanation:
Scientific notation is a way to make these numbers easier to work with.
In scientific notation, we move the decimal place until you have a number between 1 and 10.
Then you add a power of ten that tells how many places you moved the decimal.
In scientific notation, 13,224,714.066 becomes 1.3224714066 x 107.
Question 5.
25,354.011
Answer:
25354011 x 104
Explanation:
Scientific notation is a way to make these numbers easier to work with.
In scientific notation, we move the decimal place until you have a number between 1 and 10.
Then you add a power of ten that tells how many places you moved the decimal.
In scientific notation, 25,354.011 becomes 25354011 x 104
Question 6.
0.180705
Answer:
1.80705 x 10-1
Explanation:
Scientific notation is a way to make these numbers easier to work with.
In scientific notation, we move the decimal place until you have a number between 1 and 10.
Then you add a power of ten that tells how many places you moved the decimal.
In scientific notation, 0.180705 becomes 1.80705 x 10-1
Question 7.
22,294,698,171.7
Answer:
2.22946981717 x 104
Explanation:
Scientific notation is a way to make these numbers easier to work with.
In scientific notation, we move the decimal place until you have a number between 1 and 10.
Then you add a power of ten that tells how many places you moved the decimal.
In scientific notation, 22,294,698,171.7 becomes 2.22946981717 x 104
Question 8.
866.0506
Answer:
8.660506 x 102
Explanation:
Scientific notation is a way to make these numbers easier to work with.
In scientific notation, we move the decimal place until you have a number between 1 and 10.
Then you add a power of ten that tells how many places you moved the decimal.
In scientific notation, 866.0506 becomes 8.660506 x 102
Question 9.
Estimate 118.6591
Answer:
1 x 102
118.6591 x 104
Explanation:
Scientific notation is a way to make these numbers easier to work with.
In scientific notation, we move the decimal place until you have a number between 1 and 10.
Then you add a power of ten that tells how many places you moved the decimal.
In scientific notation, 118.6591 becomes 118.6591 x 104
Calculate using Order of Operations (PEMDAS).
Question 10.
4 × 2(8 – 4) + (12 – 6) × 2 + (6 – 4) × 3 + 22
Answer:
72
Explanation:
4 × 2(8 – 4) + (12 – 6) × 2 + (6 – 4) × 3 + 22
= 4 × 2(4) + 6 × 2 + 2 × 3 + 22
= 32 + 12 + 6 + 22
= 72
Question 11.
12 + 2(7 – 5) + (5 – 2) × 2 + 2(6 – 2)
Answer:
30
Explanation:
12 + 2(7 – 5) + (5 – 2) × 2 + 2(6 – 2)
= 12 + 2(2) + 3 × 2 + 2(4)
= 12 + 4 + 6 + 8
= 30
Question 12.
22 + (2 × 5) × 2 + 2(7 – 3)
Answer:
50
Explanation:
= 22 + (2 × 5) × 2 + 2(7 – 3)
= 22 + 10 × 2 + 2(4)
= 22 + 20 × 2 + 8
= 22 + 40 + 8
= 50
Question 13.
36 – 3(6 – 2) + 7 × 3 + 2(5) – 4
Answer:
51
Explanation:
36 – 3(6 – 2) + 7 × 3 + 2(5) – 4
= 36 – 3(4) + 7 × 3 + 2(5) – 4
= 36 – 12 + 21 + 10 – 4
= 51
Calculate
Question 14.
43
Answer:
64
Explanation:
am = a x a x a … a(m times) =
= 4 x 4 x 4
= 64
Question 15.
63
Answer:
216
Explanation:
am = a x a x a … a(m times) =
= 6 x 6 x 6
= 216
Question 16.
25 × 2-3
Answer:
4
Explanation:
am x an = am+n
am x a-n = am-n
= 25 × 2-3
= 25 – 3
= 22
= 4
Question 17.
109 ÷ 107
Answer:
100
Explanation:
am ÷ an = am – n
= 109 ÷ 107
= 109 – 7
= 102
= 100
Question 18.
1211 × 12-11
Answer:
1
Explanation:
am x a-n = am-n
= 1211 × 12-11
= 1211 – 11
= 120Â Â Â (a0Â = 1)
= 1
Question 19.
\(\sqrt{64}\)
Answer:
8
Explanation:
8 x 8 = 64
\(\sqrt{64}\) = 8
Question 20.
\(\sqrt{144}\)
Answer:
12
Explanation:
12 x 12 = 144
\(\sqrt{144}\)
= 12
Question 21.
\(\sqrt{625}\)
Answer:
25
Explanation:
25 x 25 = 625
\(\sqrt{625}\) = 25
Question 22.
\(\sqrt{196}\)
Answer:
14
Explanation:
14 x 14 = 196
\(\sqrt{196}\)
= 14
Question 23.
\(\sqrt{2.25}\)
Answer:
1.5
Explanation:
1.5 x 1.5 = 2.25
\(\sqrt{2.25}\)
= 1.5
Question 24.
\(\sqrt{1.69}\)
Answer:
1.3
Explanation:
\(\sqrt{1.69}\)
1.3 x 1.3 = 1.69
\(\sqrt{1.69}\) =1.3
Question 25.
Estimate \(\sqrt{8200}\)
Answer:
90
Explanation:
Estimate \(\sqrt{8200}\)
90 x 90 = 8100
Estimate \(\sqrt{8200}\) = 90
Identity the number property that each expression displays.
Question 26.
44(1) = 44
Answer:
Identity Property of Multiplication.
Explanation:
The identity property of multiplication says that the product of 1 and any number is that number.
44 × 1 = 44 times of 1.
Question 27.
19 + 0 = 19
Answer:
Identity Property of Addition.
Explanation:
When we add zero to any whole number, we get the same whole number.
Zero is an additive identity for whole numbers.
Is it an additive identity again for integers also
a + 0 = a = 0 + a
19 + 0 = 19 = 0 + 19
Question 28.
6 + (7 + 6) = (6 + 7) + 6
Answer:
Associative Property of Addition.
Explanation:
The addition is commutative for integers.
Changing the grouping of addends does not change the sum.
In general, for any two integers a and b, we can say as,
a + b = b + a
Addition is associative for integers.
In general for any integers a, b and c, we can say as,
a + (b + c) = (a + b) + c
Question 29.
3(7 + 3) = 3(7) + 3(3)
Answer:
Distributive Property.
Explanation:
a( b +c ) = (a x b) + (a x c)
Distributive property is multiplying the sum of two or more addends ,
by a number will give the same result as multiplying each addend individually,
by the number and then adding the products together.
3(7 + 3) = 3 x 10 = 30
3(7) + 3(3)
= 21 + 9
= 30
Question 30.
14 + 16 + 20 = 20 + 16 + 14
Answer:
Commutative Property of Addition.
Explanation:
Commutative property of addition is when we Change the order of addends does not change the sum.
14 + 16 + 20 = 20 + 16 + 14
a + (b + c) = (c + b) + a
= 14 + 16 + 20
= 50
Question 31.
17 = 8 + 9, 17 – 15 = 8 + 9 – 15
Answer:
Equality Property of Subtraction.
Explanation:
The subtraction property of equality states that,
when the same number is subtracted from both sides of an equality,
then the two sides of the equation still remain equal.
17 = 8 + 9,
17 = 17
17 – 15 = 8 + 9 – 15
2 = 17 – 15 = 2
Question 32.
43 × 0 = 0
Answer:
Zero Property of Multiplication.
Explanation:
According to the zero property of multiplication,
the product of any number and zero, is zero.
a x 0 = 0 = 0 x a
43 x 0 = 0 = 0 x 43
Question 33.
35 = 18 + 17, 35 + 9 = 18 + 17 + 9
Answer:
Equality Property of Addition.
Explanation:
The addition property of equality states that,
if the same amount is added to both sides of an equation.
35 = 18 + 17,
35 = 35
35 + 9 = 18 + 17 + 9
44 = 44
Solve the equation and indicate the point on the number line that corresponds with the answer.

Question 34.
-5 + 5 – 5
Answer:
-5 – Point A
Explanation:
In Maths, number lines are the horizontal straight lines in which the integers are placed in equal intervals.

– 5 + 5 – 5 = – 5
Question 35.
-10 + 4 – 1
Answer:
-7 – Point B
Explanation:
In Maths, number lines are the horizontal straight lines in which the integers are placed in equal intervals.

-10 + 4 – 1
= -11 + 4
= -7
Question 36.
-7 + (-4) + 3
Answer:
-8 – Point D
Explanation:
In Maths, number lines are the horizontal straight lines in which the integers are placed in equal intervals.

-7 + (-4) + 3
= -7 – 4 + 3
= – 11 + 3
= – 8
Question 37.
9 – 5 + (-7)
Answer:
-3 – Point C
Explanation:
In Maths, number lines are the horizontal straight lines in which the integers are placed in equal intervals.

9 – 5 + (-7)
= 9 – 5 – 7
= 9 – 12
= – 3
Calculate.
Question 38.
-60 × 25
Answer:
-1500
Explanation:
Multiply the given numbers or factors starting from ones, tens and so on..
Once you get the product or answer add minus sign to the answer.

Question 39.
-135 ÷ 15
Answer:
-9
Explanation:
-135 ÷ 15
= -135 ÷ 15  (15 x – 9 = -135)
= -9
Question 40.
12 × (-5 – 7) ÷ (8 – 16)
Answer:
78
Explanation:
12 × (-5 – 7) ÷ (8 – 16)
12 × -12÷ -8
3 x 6 ÷ (8 – 16)
Question 41.
630 ÷ -70
Answer:
-9
Explanation:
630 ÷ -70
= 63 ÷ -7
= -9
Question 42.
14(-6) ÷ -7
Answer:
12
Explanation:
14(-6) ÷ -7
= -14 x 6 ÷ -7
= 14 x 6 ÷ 7
= 2 x 6
= 12
Question 43.
-5 × (-3) × (14 – 18)
Answer:
-60
Explanation:
-5 × (-3) × (14 – 18)
= -5 ×-3 × -4
= -5 ×12
= – 60
Question 44.
-24 × -3 ÷ -2
Answer:
-36
Explanation:
-24 × -3 ÷ -2
= -24 × -3 ÷ -2
= -24 × -3 ÷ -2
= -36
Question 45.
15 × -3 ÷ 9
Answer:
-5
Explanation:
15 × -3 ÷ 9
= 15 × -3 ÷ 9
= -5
Question 46.
(19 – 23) × (5 – 4) × (17 – 15)
Answer:
-8
Explanation:
(19 – 23) × (5 – 4) × (17 – 15)
= (19 – 23) × 1 × 2
= -4 × 2
= -8
Question 47.
How many times larger is the total U.S. federal budget of $4 × 109 than the budget for education of $8 × 107?
Answer:
50
Explanation:
The total U.S. federal budget of $4 × 109 than the budget for education of $8 × 107
$4 × 109 of $8 × 107
= \(\frac{4 × 109}{8 × 107}\)
= \(\frac{1 × 102}{2}\)
= 0.5 × 102
= 50
Convert the following to fractions.
Question 48.
7\(\frac{2}{3}\)
Answer:
\(\frac{23}{3}\)
Explanation:
7\(\frac{2}{3}\)
Convert mixed fraction to improper fraction.
= 7\(\frac{3 x 7 + 2}{3}\)
= \(\frac{23}{3}\)
Question 49.
0.262626…
Answer:
\(\frac{26}{99}\)
Explanation:
0.26262626…
let
x = 0.262626…————-(Eq 1)
multiplying by 100 on both side
100 x = 26.262626….————-(Eq 2)
on subtracting Eq 1 from Eq 2

x = \(\frac{26}{99}\)
Question 50.
1.56
Answer:
\(\frac{156}{100}\) or \(\frac{39}{25}\)
Explanation:
By multiplying both the numerator and denominator by 100.
\(\frac{1.56 x 100}{100}\)
= \(\frac{156}{100}\)
Dividing both the numerator and denominator by 4.
= \(\frac{39}{25}\)
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