Adding Integers

Sebastian was in a hotel lobby and took the elevator up 7 floors to his room. Then he took the elevator down 9 floors to the parking garage. He described his movement with the expression below.

 $9+\left(-7\right)$  

• Sebastian should have used –9 and 7.

• Sebastian should have started at zero before adding –7.

• Sebastian should have switched the two addends and written  $-7+9$   .

• Sebastian should have used 0 and –9.

A meteorologist used the expression below to describe how the temperature changed.

 $-5+\left(-4\right)$  

• The temperature was –5 degrees, then it increased 4 degrees.

• The temperature was –5 degrees, then it decreased 4 degrees.

• The temperature was 5 degrees, then it increased 4 degrees.

• The temperature was 5 degrees, then it decreased 4 degrees.

The temperature at 9 a.m. is 2 degrees. The temperature rises 3 more degrees by noon. Which expression describes the temperature at noon?

• 
  

  $2+3$
  

• $2+\left(-3\right)$

• $-2+\left(-3\right)$

• $-2+3$

Sean says that to add a number to –100 and still have –100 is to add zero. Candice says that she can add two numbers to –100 and still have –100. Who is correct and why?

• Sean is correct because adding any numbers other than zero will result in a different number.

• Candice is correct because if the two numbers total 100, then the sum will be –100.

• They are both correct because adding two numbers that are opposites is equivalent to adding zero.

• Neither is correct because adding any number to –100 will result in a different number.

What is the value of the expression?

 $-16+12$  

•  $-28$  

•  $-4$  

•  $4$  

•  $28$  

What is the value of the expression?

 $-8+19+8$  

• 0

• 11

• 19

• 35

Which expression has the same sum as the one below?

 $-15+6$  

•  $6+15$  

•  $-6+\left(-15\right)$  

•  $15+\left(-6\right)$  

•  $6+\left(-15\right)$  

Which addition does the model below represent?

• 
  

  $3+\left(-1\right)$
  

• $3+4$

• $3+\left(-4\right)$

• $3+1$

What is the sum of

 $-1+\left(-3\right)$  

•  $-4$  

•  $-3$  

•  $2$  

•  $3$  

Carlos is using a number line to add another integer to –4. He begins by showing –4 on the number line, as shown below. Carlos adds the other integer on the number line and says that the sum is negative.

Which is true of the number Carlos added to –4?

• The number must be a negative integer.

• The number must be a positive integer.

• The number could be 3 or any integer less than 3.

• The number could be 4 or any integer greater than 4.