1.
a. Is 3.2 − 5.7 positive, negative, or zero?
A. negative
B. zero
C. positive
b. Is 3.2 − (− 5.7) positive, negative, or zero?
A. negative
B. zero
C. positive
2.
a. Is 2 fifths , minus . open , negative , 5 sixths , close positive, negative, or zero?
A. positive
B. negative
C. zero
b. Is 2 fifths , minus . open , 5 sixths , close positive, negative, or zero?
A. zero
B. positive
C. negative
3. Decide if each expression describes a difference that is positive, negative, or zero.
a. Is − 4.5 − (− 6.1) positive, negative, or zero?
A. negative
B. positive
C. zero
b. Is − 4.5 − 6.1 positive, negative, or zero?
A. positive
B. zero
C. negative
4. Draw a point on a number line to indicate the difference 1 , and 1 third , minus 4 , and 5 sixths , .
5. Which number line in Figure 1 models 1 fourth , minus . open , negative , 5 eighths , close correctly?
6. Find the value of the expression 11.0 − (− 2.1).
7. The temperature in a town is 36.6 ° F during the day and −12.6°F at night. Find the difference in the temperatures.
8. The freezing point of Chemical A is − 70.2 °C. The freezing point of Chemical B is − 164.21 °C. Which chemical has a higher freezing point? How much higher is it?
A. The freezing point of Chemical B is °higher than Chemical A's freezing point.
B. The freezing point of Chemical A is °higher than Chemical B's freezing point.
9.
a. Writing Is 5.3 − 5.3 positive, negative, or zero?
A. positive
B. negative
C. zero
b. Is 5.3 − (− 5.3) positive, negative, or zero?
A. negative
B. positive
C. zero
c. How can you use the answer for the first part to help you answer the second part?
10.
a. Reasoning Is negative , 1 third , minus , 4 fifths positive, negative, or zero?
A. negative
B. positive
C. zero
b. What can you say about the sign of the difference when you subtract − m − n, for any positive rational numbers m and n?
A. The difference is always zero.
B. The difference is always negative.
C. The difference is always positive.
D. The difference is negative if |n|>|m| and positive if |n|<|m|.