Name _____________________________________ Period ____ NNSO #7 Integers - Notes and Practice
1. What are integers? Integers are the set of all WHOLE numbers. Integers include 3 things:
A) All of the WHOLE numbers greater than zero. We call these positive integers. Positive numbers may
be written with a positive sign in front of them (+3), but they are usually written without a sign. (1, 2,
54, 98, etc.) We read positive number like +9 two ways: Positive 9 or 9
B) All of the WHOLE numbers less than zero. We call these negative integers. Negative numbers must
be written with a negative sign in front of them (-3). We read negative numbers like -12 only one way:
negative 12
C) Zero. This integer NEVER has a sign on it. It is neutral, which means it is neither positive nor
negative.
2.
Looking at integers on a number line.
A) Notice that zero is right in the middle. It is not positive, and it is not negative.
B) The further to the left a number is on the number line, the SMALLER (littler) the number is.
C) The further to the right a number is on the number line, the BIGGER that number is.
D) Examples: 1) -5 is further to the left than 4, so -5 < 4
2) -1 is further to the right than -3, so -1>-3
E) When comparing negative numbers, we have to think the opposite of what we do when we compare
positive numbers. The bigger the digit is on the negative number, the smaller its value is. That
means that -34 is smaller than -4. -1 is bigger than -7.
3. Writing integers for situations described in words.
Example: Lose 5 pounds = -5
A) Words that signal a positive integer: increase, gain, earn, rise, go up, grow, deposited, above, profit,
bonus, earnings, winnings, after,
B) Words that signal a negative integer: decrease, lose, fall, go down, descend, shrink, withdraw, below,
drop, penalty, before, behind, debt
*Note: As you come across or think of other words that signal negatives or positives, be sure to add them
to your list above! 
C) Practice. For each situation write an integer to represent it.
1) gained 12 yards _______ 2) 5 yard penalty _______
3) 40 feet above sea level _______
4) earned 9 dollars _______ 5) 12 feet under water _______ 6) withdrew $50 _______
4. Writing expressions and evaluating them using a number line to help us.
A) When we read a scenario involving numbers, we can write integers to represent the situation. Since we
will put the integers together, we can write an expression using addition signs. To find the value of
the expression, we can then use a number line. Here’s how:




Put your finger on the number line starting with the first number you wrote
The second number will be how many “jumps” we move.
If the number is negative, jump to the LEFT.
If the number is positive, jump to the RIGHT.
The number where you end up is the value of the expression.
If you have more than 2 numbers, then just continue jumping left/right until you have used all of the
numbers.
B) Examples:
1) The Steelers lost 2 yards on the first play and gained 8 yards on the second play.
-2
+
8

Now put them together: -2 plus +8 which is the same as -2 + +8

Put your finger on -2 on the number line above.

Jump 8 spaces to the ______________ because 8 is positive

You end up landing on ____________. So the value of the expression -2 + +8 is ___________
2) Throughout the day, the temperature rose 6 degrees. In the evening, it fell 13 degrees.
+
6
-13

Now put them together: +6 plus -13 which is the same as

Put your finger on +6 on the number line above.

Jump 13 spaces to the ______________ because 13 is negative

You end up landing on _________. That’s the value of this expression:
+
6 + -13
+
6 + -13 = ________
Name ______________________________________ Period _____ Representing Situations With Integers
Write an integer to represent each situation listed below.
1) a savings of $10 ________
25) climbing up 150 feet ________
2) a gain of 4 yards ________
26) jumping down 5 steps ________
3) a decrease of 15 pounds ________
27) a decrease of 24 cars ________
4) 3 feet under water ________
28) a increase of 20 cm. ________
5) a 12-foot deep crater ________
29) 15% off ________
6) an expense of $39 ________
30) 6 % sales tax _______
7) 50 years ago ________
31) 6 days behind schedule ________
8) a profit of $150 ________
32) 4 weeks ahead of schedule ________
9) a debt of $175 ________
33) golf score of 2 over par ________
10) a 17 degree rise in temperature ________
34) golf score of 1 under par ________
11) a $25 gift ________
35) golf score of par (not over, not under) _______
12) a loss of 7 points ________
36) sinking 45 feet ________
13) 5 miles below sea level ________
37) flying 1,000 feet above the ground ________
14) 10 seconds before lift-off ________
38) digging a hole 7 meters deep ________
15) 30 seconds after lift-off ________
39) take the elevator up 15 floors ________
16) 100 feet above sea level ________
40) ride the elevator down 21 floors ________
17) a 15 degree drop in temperature ________
Think About It – Write About It
18) a 20 yard penalty ________
41) Could a rectangle ever have an area that is a
negative number? Explain your answer.
19) earnings of $45 ________
_____________________________________
20) 14 years from now ________
_____________________________________
21) a stock price drop of $1 ________
_____________________________________
22) 6 laps behind the lead car ________
_____________________________________
23) a $50 bonus ________
_____________________________________
24) a bill for $40 ________
Name ________________________________________________________ Period _____ Integer Scenarios
Read each scenario and write an addition expression using integers to represent the situation. Use a
number line to find the value of the expression.
1) The team lost 5 yards on the first down and gained 12 yards on the second down.
2) At noon, the temperature had risen 10 degrees, but it fell 18 degrees by midnight.
3) Bill climbed up 17 feet. Then he slid back down the hill 8 feet.
4) Erica withdrew 11 dollars on Monday. On Friday, she deposited 40 dollars into her account.
5) Shelby earned $8 babysitting. She repaid her mom the $8 she had borrowed last week.
6) On his diet, Jermaine lost 7 pounds. After exercising and building muscles, he gained 4 pounds.
7) The scuba diver dove 9 feet below sea level to look at coral and went 11 feet deeper to see a rare fish.
8) During the blizzard, the temperature fell 12 degrees. That night, the temperature fell another 4 degrees
9) Skylar hired 7 new people, but he fired 3 other people.
10) The dolphin swam 21 feet into the ocean and then swam 12 feet upward toward the surface of the water.
11) Steve missed 7 points on the test. However, he earned 4 bonus points.
12) Herman dropped 13 pieces of paper, but he only picked up 9 of the pieces.
13) Your mom folded 15 shirts, and your sister folded another 16 shirts.
14) Delia lost 2 baby teeth this month. Her best friend has not lost any teeth yet.
15) Jacy filled 18 water balloons. 12 of the balloons burst.
Challenge: Harry had $99. He spent $15, borrowed $16 from his mom, earned $11, lost $29, found $36, lent
his brother $34 and bought lunch for $4.23. How much money does Harry have now? Are all the
numbers in this problem integers? If not, which ones aren’t integers?