Integers Introduction — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. A diver descended 12 feet then rose 4 feet. Final depth is -8.
-12 plus 4 equals -8, meaning the diver is eight feet below start.
2. Subtract 7 from 2 by adding -7 to 2.
Adding -7 to 2 gives the same answer as 2 minus 7, which is -5.
3. Account starts at $40, fee of $55 applied. Balance is -15.
40 minus 55 equals -15, an overdraft of fifteen dollars.
4. Lost 3 points, lost 2 points, gained 10. Net change is 5.
-3 plus -2 plus 10 equals 5, the final net change.
5. Subtracting -8 is the same as adding 8.
Subtracting a negative integer is identical to adding its positive opposite.
6. Game points: -4, +9, -2, total equals 3.
-4 plus 9 minus 2 equals 3, the running point total.
7. Withdrew $25 from $25 balance leaves 0.
25 minus 25 equals 0, leaving the account empty but not negative.
8. Phrase 'lost ten dollars' written as integer is -10.
Losses are represented by negative integers in real-world translations.
9. Rewrite 6 minus negative 4 as 6 plus 4.
Subtracting -4 equals adding 4, giving 6 plus 4 equals 10.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
Owe $9
→ -9
-9
Earn $12
→ +12
+12
Drop 6 floors
→ -6
-6
Climb 8 stairs
→ +8
+8
Negative integers represent loss or descent; positive integers represent gain or ascent.