# Free Exponents and Powers 02 Practice Test - 7th grade

In power notation, 81625 can be expressed as ___.

A.

(53)4

B.

(35)4

C.

(3  5)4

D.

(34)5

#### SOLUTION

Solution : B and C

81=3×3×3×3=34

625=5×5×5×5=54

81625=3454=(35)4

(1)even number=+1

Hence, (3  5)4  is also correct.

Find the value of (23)5×36×18×16.
___

#### SOLUTION

Solution :

Simplifying  (23)5×36×18×16,

we get  (2535)×36×123×12×3
= 25×3635×23×2×3

= 25×3636×24

=2

If a = 2 and b = 3, find the value of ab.

A.

16

B.

32

C.

64

D.

8

#### SOLUTION

Solution : D

Putting a=2 and b=3,

we get 23=2×2×2=8.

Find the value of 53×23.

A.

103

B.

1

C.

10

D.

1000

#### SOLUTION

Solution : A and D

Here the  two terms  53 and 23 have different bases, but same exponents.

53×23=(5×5×5)×(2×2×2)
=(5×2)×(5×2)×(5×2)
=(5×2)3
=103=1000
or
53×23=(5×2)3=103=1000

Write 0.1234 in standard form.

A.

It's already in standard form

B.

1.234×101

C.

12.34×102

D.

1234×104

#### SOLUTION

Solution : B

In standard form, any number is expressed in powers of 10. The decimal number must be in between 1 and 10.

0.1234=1.23410=1.234×101

72×22 =___

#### SOLUTION

Solution :

72=49
22=4

72×22=(7×2)2=142=196

Express 512×729 in exponential form:

A.

28×33

B.

29×36

C.

27×34

D.

29×37

#### SOLUTION

Solution : B

512=2×2×2×2×2×2×2×2×2=29
729=3×3×3×3×3×3=36

=29×36

The value of (33×23×50) is:

A.

216

B.

215

C.

201

D.

219

#### SOLUTION

Solution : A

33=27

23=8

50=1

27×8×1=216

In 104,10 is called the __ and 4 is called the exponent.

#### SOLUTION

Solution :

Here, 10 is called the base.

Say true or false:

(25)2=(25)2

A.

True

B.

False

#### SOLUTION

Solution : B

LHS = (25)2=425

RHS = (25)2=425

Hence, the given statement is false.