This handy Spectrum Math Grade 4 Answer Key Chapter 4 Posttest provides detailed answers for the workbook questions.

Multiply.

Question 1.
a.

Multiply the given number 72 with 4 by following the below procedure and the result 288 as shown below.

b.

Multiply the given number  24 with 8 by following the below procedure and the result is 192 as shown below.

c.

Multiply the given number 339 with 2 by following the below procedure and the result 678 as shown below.

d.

Multiply the given number  34 with 8 by following the below procedure and the result 272 as shown below.

e.

Multiply the given number 150 with 9 by following the below procedure and the result 1350 as shown below.

f.

Multiply the given number  333 with 2 by following the below procedure and the result 666 as shown below.

g.

Multiply the given number 93 with 2 by following the below procedure and the result is 666 as shown below.

Question 2.
a.

Multiply the given number 242 with 2 by following the below procedure and the result 484 as shown below.

b.

Multiply the given number 64 with 8 by following the below procedure and the result 512 as shown below.

c.

Multiply the given number 31 with 2 by following the below procedure and the result is 217 as shown below.

d.

Multiply the given number  300 with 21 by following the below procedure and the result 6300 as shown below.

e.

Multiply the given number 7 with 9 by following the below procedure and the result 63 as shown below.

f.

Multiply the given number 173 with 28 by following the below procedure and the result 4834 as shown below.

g.

Multiply the given number 90 with 8 by following the below procedure and the result 720 as shown below.

Question 3.
a.

Multiply the given number  3417 with 7 by following the below procedure and the result 23919 as shown below.

b.

Multiply the given number 728 with 1 by following the below procedure and the result 728 as shown below.

c.

Multiply the given number 22 with 3 by following the below procedure and the result 66 as shown below.

d.

Multiply the given number 207 with 21 by following the below procedure and the result 4347 as shown below.

e.

Multiply the given number 900 with 6 by following the below procedure and the result 5400 as shown below.

f.

Multiply the given number 79 with 4 by following the below procedure and the result 316 as shown below.

g.

Multiply the given number 643 with 7 by following the below procedure and the result 4501 as shown below.

Question 4.
a.

Multiply the given number 743 with 2 by following the below procedure and the result 1486 as shown below.

b.

Multiply the given number 439 with 10 by following the below procedure and the result 4390 as shown below.

c.

Multiply the given number 117 with 23 by following the below procedure and the result 2691 as shown below.

d.

Multiply the given number 946 with 3 by following the below procedure and the result 5658 as shown below.

e.

Multiply the given number 2981 with 6 by following the below procedure and the result 17886 as shown below.

f.

Multiply the given number 200 with 9 by following the below procedure and the result 1800 as shown below.

g.

Multiply the given number 555 with 40 by following the below procedure and the result 22200 as shown below.

List the factors of each number. Then, label each number as prime or composite.

Question 5.
85
Factors
_______________________
Prime or Composite?
_______________________
Given number is 85
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 85 =  1, 5, 17, 85
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
5, 17 is a prime number
85 is a composite number since it has more than one factor.

Question 6.
59
Factors
_______________________
Prime or Composite?
_______________________
Given number is 59
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 43 = 1, 59
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
59 is a prime number

Question 7.
15
Factors
_______________________
Prime or Composite?
_______________________
Given number is 15
From the definition of factors we know factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Factors of 15 =  1, 3, 5, 15.
Prime numbers are the ones that have one and itself as factors.
1 is neither prime nor composite
3,5 is a prime number
15 is a composite number since it has more than one factor.

Question 8.
Factors
_______________________
Prime or Composite?
_______________________
factors of a number are nothing but the numbers that divide the given number exactly and leaves no remainder.
Numbers which have more than one factor is called a composite.

Solve each problem.

Question 9.
Mrs. Rockwell checked on how much time her students spend doing homework. If all 23 students spend 20 hours a week, how much homework do the students do in a week?
They do _________ hours of homework a week.
Number of students = 23
Number of hours spent by students in a week =20
Number of hours of homework in a week=?
= 23 x 20 = 460
Therefore 460 hours spent by the students for the homework.

Question 10.
A cable program loans channel boxes to 21 community centers for a trial program. If there are 12 boxes for each center, how many boxes are being loaned?
There are __________ boxes being loaned.
Number of channel boxes to community = 21
Total number of boxes for each center = 12
Number of boxes being loaned=?
= 21 x 12 = 252
Therefore 252 boxes are loaned.

Question 11.
A girls’ club is trying to get into the record books for the most hair braids. There are 372 girls. If each girl braids her hair into 40 little braids, how many braids will they have?
They will have __________ braids.
Number of girls = 372
Number of little braids = 40
Number of braids they contain = ?
= 372 x 40 =14,880
Totally, 14,880 braids are present.

Write the equation. Then, solve the problem.

Question 12.
Mrs. Numkena’s science class raised tadpoles. If 35 students raised 23 tadpoles each, how many tadpoles did the class have?
_____ × ____ = ____
Number of students = 35
Number of each tadpoles = 23
Number of tadpoles present in the class=?
= 35 x 23 = 805