Addition of Integers

Maria saved 200 dollars and then she spent 150 dollars. How much money does Maria have now?

• Maria has 40 dollars left.

• Maria has 50 dollars left.

• Maria has 55 dollars left.

• Maria has 45 dollars left.

Answer explanation

Saved 200 can be represented by + 200

And

is the + sign Spent 150 can be represented by  -150

We get

200 + -150 and 200 + -150 = 50

Maria has 50 dollars left.

A submarine at 21 feet below sea level suddenly moves up about 6 feet.  At what depth is the submarine located now?

• The submarine is 20 feet below sea level.

• The submarine is 10 feet below sea level.

• The submarine is 25 feet below sea level.

• The submarine is 15 feet below sea level.

Answer explanation

21 feet below sea level can be represented by - 21

We can use the + sign Moves up about 6 feet can be represented by  +6

We get -21 + +6 and -21 + +6 = -15

The submarine is 15 feet below sea level.

A football team gained 6 yards and then lost 10 yards. Where is the football team now?

• Overall the football team has lost 4 yards.

• Overall the football team has lost 5 yards.

• Overall the football team has lost 6 yards.

• Overall the football team has lost 7 yards.

Answer explanation

Gained 6  can be represented by + 6

And is the + sign Lost 10 can be represented by  -10

We get +6 + -10 and +6 + -10 = -4

Overall the football team has lost 4 yards.

Steve had 140 dollars. He loaned 50 dollars to a friend, spent 31 dollars, and received his 80 dollars paycheck from work. How much money does he have now?

• Steve has now 129 dollars.

• Steve has now 139 dollars.

• Steve has now 149 dollars.

• Steve has now 159 dollars.

Answer explanation

Had 140 dollars can be represented with +140

Loaned 50 can be represented by  -50

Spent 31 can be represented by  -31

Received his 80 can be represented by +80

We get 140 + (-50) + (-31) + 80  = 139

Steve has now 139 dollars.

Encircle the answer using horizontal number line.

10 + (-6) = N

Answer explanation

Encircle the answer using horizontal number line.

(-1) + (-8) = N

Answer explanation

Encircle the answer using horizontal number line.

5 + (-8) = N

Answer explanation

Encircle the answer using horizontal number line.

(-6) + 9 = N

Answer explanation

(-69) + 49 = N

(a)  

(-400) + (-150) = N

(a)