Question 1

Evaluate.
--23.7 + (-13.1)
A)-10.6
B)-36.8
C)10.6
D)36.8

Accepted Answer

To evaluate -23.7 + (-13.1), we need to add the two numbers with opposite signs. 
We can use the rule: Same sign, add and keep the sign. Opposite sign, subtract and take the sign of the larger number. 
In this case, both numbers are negative. So, we add them and keep the negative sign. 
|-23.7| > |-13.1|. So, our answer is negative and equal to |-23.7| - |-13.1| = -36.8. 
Therefore, the best choice is B. When adding two negative numbers, we add their absolute values and assign the negative sign to the total. Therefore, 23.7 + 13.1 = 36.8, and since both numbers were negative, the answer is -36.8.

Question 2

Evaluate.
--12 + (-9)
A)-3
B)-21
C)3
D)21

Accepted Answer

When adding negative numbers, we add the absolute values and give the sum a negative sign. So, |-12| + |-9| = 21 and since we are adding two negatives, the answer is -21. Therefore, the correct choice is B.

Question 3

Solve the problem.
-On part of a scenic tour of underground caves, Dave and Neil started at an elevation of -30 feet. They then rose 23 feet. What was their elevation at this point?
A)-7 ft
B)7 ft
C)-53 ft
D)53 ft

Accepted Answer

Starting at -30 feet and rising 23 feet results in an elevation of -30 + 23 = -7 feet.

Question 4

Evaluate.
-8 - (-5)
A)3
B)-13
C)13
D)-3

Accepted Answer

To subtract a negative number, we change its sign to positive and then perform addition. So, 8 - (-5) becomes 8 + 5 which equals 13. Therefore, the correct choice is C. When subtracting a negative number, we can rewrite it as adding the opposite of that negative number. So, 8 - (-5) is the same as 8 + 5, which equals 13. Therefore, the best choice is C.

Question 5

Solve the problem.
-Lauren scored 12 points in her basketball game on Monday, 15 on Wednesday, 5 on Friday, and 2 on Saturday. Find her total points scored for the week.
A)32 points
B)33 points
C)34 points
D)35 points

Accepted Answer

The answer of Solve the problem.
-Lauren scored 12 points in...

Question 6

Evaluate.
--3 + 16
A)19
B)13
C)-13
D)-19

Accepted Answer

-3 + 16 
= 13 When we add -3 and 16 together, we get 13. Therefore, the answer is B) 13.

Question 7

Evaluate.
-$\frac { 1 } { 6 } + \left( - \frac { 1 } { 6 } \right)$
A) $\frac { 2 } { 3 }$
B)0
C) $- \frac { 1 } { 3 }$
D) $\frac { 1 } { 3 }$

Accepted Answer

When you add a number to its negative, the result is 0. Here, $\frac{1}{6} + (-\frac{1}{6}) = 0$.

Question 8

Evaluate.
-4.144 + (-6.042)
A)-10.086
B)-1.898
C)-10.186
D)1.898

Accepted Answer

To evaluate, we simply add the two numbers together:

4.144 + (-6.042) = -1.898

The answer is negative since we are adding a negative number to a positive number, which results in a smaller number. Therefore, the best choice is B.

Question 9

Evaluate.
--7.9 - (-1.1)
A)-6.8
B)6.8
C)9
D)-9

Accepted Answer

Subtracting a negative number is the same as adding its positive counterpart, so -7.9 - (-1.1) equals -7.9 + 1.1, which equals -6.8.

Question 10

Evaluate.
-$\frac { 2 } { 5 } + \left( - \frac { 1 } { 5 } \right)$
A) $- \frac { 1 } { 5 }$
B) $- \frac { 3 } { 5 }$
C) $\frac { 3 } { 5 }$
D) $\frac { 1 } { 5 }$

Accepted Answer

When adding $\frac{2}{5}$ and $-\frac{1}{5}$, you get $\frac{1}{5}$ because the denominators are the same, so you simply add the numerators: $2 + (-1) = 1$.

Question 11

Evaluate.
-$| - 2 | + 29$
A)31
B)27
C)-31
D)-27

Accepted Answer

The absolute value of -2 is 2, so $| - 2 | + 29 = 2 + 29 = 31$.

Question 12

Evaluate.
-$- | 2 | + | 10 |$
A)-12
B)8
C)-8
D)12

Accepted Answer

The absolute value of 2 is 2, and the absolute value of 10 is 10. So, the expression becomes -2 + 10, which equals 8.

Question 13

Evaluate.
-7 - 10
A)3
B)-3
C)-17
D)17

Accepted Answer

7 - 10 is a subtraction problem, and subtracting 10 from 7 results in a negative answer, which is represented by choice B (-3). 7 - 10 can be simplified as -3. Therefore, the answer is B (-3).

Question 14

Evaluate.
-$- | - 13 | + | - 12 | + ( 5 + | - 28 | )$
A)34
B)22
C)8
D)32

Accepted Answer

The expression simplifies to $-13 + 12 + (5 + 28)$, which equals 32.

Question 15

Solve the problem.
-The Neighborhood Lemonade Stand, Inc. reported net incomes of -$424, -$186, and -$449 for the past three years. What was its total net income for these three years?
A)$1059
B)-$1059
C)-$635
D)-$610

Accepted Answer

To find the total net income for the three years, we need to add the individual net incomes. However, since all three net incomes are negative, the total net income will be negative as well. Adding -$424, -$186, and -$449 gives us a total of -$1059. Therefore, the best choice is B. To find the total net income, we need to add up the incomes for all three years. The negative signs indicate losses rather than profits. Therefore, the sum of the three net income values is: 
-$424 + (-$186) + (-$449) = -$1059 
So, the total net income for these three years was -$1059. Choice B is the only option that matches this value.

Question 16

Evaluate.
--10 - (-4)
A)-14
B)6
C)14
D)-6

Accepted Answer

Subtracting a negative number is the same as adding its positive counterpart, so -10 - (-4) = -10 + 4 = -6.

Question 17

Evaluate.
-0.66 - (-0.36)
A)0.3
B)1.12
C)1.02
D)0.2376

Accepted Answer

To subtract a negative number, we can add the opposite positive number. So, 0.66 - (-0.36) becomes 0.66 + 0.36 = 1.02. Therefore, the correct choice is C. To subtract a negative number, we can change the sign of the second number and then add it to the first number. So, 0.66 - (-0.36) becomes 0.66 + 0.36 which equals 1.02. Therefore, the answer is C.

Question 18

Solve the problem.
-At the start of a chemistry experiment, Sarah measured the temperature of a liquid to be -3° C. At the end of the experiment, it had risen 32° C. What was the liquid's temperature at the end of the experiment?
A)29° C
B)-35° C
C)-29° C
D)35° C

Accepted Answer

The liquid's temperature at the end of the experiment was -3° C + 32° C = 29° C.

Question 19

Evaluate.
--7 - 13
A)-20
B)-6
C)20
D)6

Accepted Answer

To solve -7 - 13, we can combine the two numbers by adding their magnitudes and then putting a negative sign on the result. So we have |-7| + |-13| = 7 + 13 = 20. Putting a negative sign in front of that gives us -20. Therefore, the correct answer is choice letter A, -20. To calculate -7 - 13, you need to subtract 13 from -7, which gives you -20. Therefore, the correct answer is A) -20.

Question 20

Evaluate.
-$\frac { 1 } { 7 } + \left( - \frac { 1 } { 12 } \right)$
A) $- \frac { 5 } { 84 }$
B) $\frac { 5 } { 7 }$
C) $\frac { 5 } { 84 }$
D) $- \frac { 5 } { 7 }$

Accepted Answer

To add the fractions $\frac{1}{7}$ and $-\frac{1}{12}$, find a common denominator, which is 84. Convert the fractions: $\frac{1}{7} = \frac{12}{84}$ and $-\frac{1}{12} = -\frac{7}{84}$. Adding them gives $\frac{12}{84} - \frac{7}{84} = \frac{5}{84}$.

Quiz 1: Basic Concepts

Evaluate. --23.7 + (-13.1)

Evaluate. --12 + (-9)

Solve the problem. -On part of a scenic tour of underground caves, Dave and Neil started at an elevation of -30 feet. They then rose 23 feet. What was their elevation at this point?

Evaluate. -8 - (-5)

Solve the problem. -Lauren scored 12 points in her basketball game on Monday, 15 on Wednesday, 5 on Friday, and 2 on Saturday. Find her total points scored for the week.

Evaluate. --3 + 16

Evaluate. - $\frac { 1 } { 6 } + \left( - \frac { 1 } { 6 } \right)$

Evaluate. -4.144 + (-6.042)

Evaluate. --7.9 - (-1.1)

Evaluate. - $\frac { 2 } { 5 } + \left( - \frac { 1 } { 5 } \right)$

Evaluate. - $| - 2 | + 29$

Evaluate. - $- | 2 | + | 10 |$

Evaluate. -7 - 10

Evaluate. - $- | - 13 | + | - 12 | + ( 5 + | - 28 | )$

Solve the problem. -The Neighborhood Lemonade Stand, Inc. reported net incomes of -$424, -$186, and -$449 for the past three years. What was its total net income for these three years?

Evaluate. --10 - (-4)

Evaluate. -0.66 - (-0.36)

Solve the problem. -At the start of a chemistry experiment, Sarah measured the temperature of a liquid to be -3° C. At the end of the experiment, it had risen 32° C. What was the liquid's temperature at the end of the experiment?

Evaluate. --7 - 13

Evaluate. - $\frac { 1 } { 7 } + \left( - \frac { 1 } { 12 } \right)$