7.1 · Part II
Second Practice Form · Independent Application and Spiral Review
Integer · Opposite
- Integers: Positive whole numbers, negative whole numbers, and zero (..., -2, -1, 0, 1, 2, ...)
- Opposites: Numbers that are the same distance from 0 in opposite directions (e.g. -5 and 5)
- The opposite of the opposite of a number is the number itself: -(-a) = a
- Integer (Número entero) — The counting numbers, their opposites, and 0.
- Opposite (Opuesto) — A number that is the same distance from 0 as another number, but on the other side of 0.
- Negative number (Número negativo) — A number less than 0, written with a − sign. On a number line it sits to the left of 0.
- Positive number (Número positivo) — A number greater than 0. On a number line it sits to the right of 0.
- Number line (Recta numérica) — A straight line where numbers are placed in order. It extends to the left of 0 to show values less than 0.
- The most common mistake in this lesson is thinking that the opposite of a negative integer is still negative — for example, saying the opposite of -7 is -7, or that the opposite of -12 is -24. Opposites are the same DISTANCE from 0 but on OPPOSITE sides of 0, so taking an opposite always changes the direction and never changes the distance: the opposite of -7 is 7 and the opposite of -12 is 12. The one exception is 0, which is 0 units from itself and is therefore its own opposite. Before you submit, count the units from 0 and check that your answer is on the other side.
-
1 GUIDED FILL
An account is overdrawn by $10. Write the integer, then its opposite.
- 1Below/lost/owed means negative: the integer is ___.
- 2The opposite sits the same distance from 0 on the other side: ___.
- 3Both are ___ units from zero, and here zero means a balance of $0.
Final answer: -
2 GUIDED FILL
A diver is 12 feet below the surface. Write the integer, then its opposite.
- 1Below/lost/owed means negative: the integer is ___.
- 2The opposite sits the same distance from 0 on the other side: ___.
- 3Both are ___ units from zero, and here zero means the surface.
Final answer: -
3 MULTIPLE CHOICE
At 6 a.m. in Reykjavik the temperature was -12°C. At 2 p.m. it was the opposite of the 6 a.m. temperature, and at 11 p.m. it was the opposite of the 2 p.m. temperature. What were the temperatures at 2 p.m. and 11 p.m.?
- A12°C and -12°C
- B-12°C and 12°C
- C12°C and 24°C
- D0°C and 12°C
✏️ Workspace & Solution Steps -
4 MULTIPLE CHOICE
A football team starts at the line of scrimmage, which is 0. During one series they had a 10-yard loss, a 4-yard gain, a 3-yard loss, and a 21-yard gain. Where does the series leave them?
- A12 yards past the line of scrimmage
- B8 yards past the line of scrimmage
- C18 yards past the line of scrimmage
- D38 yards past the line of scrimmage
✏️ Workspace & Solution Steps -
5 MULTIPLE CHOICE
Claim: “The opposite of a number is always negative.” Always, sometimes, or never true?
- ASometimes — it is negative only when the original number is positive
- BAlways — that is what taking the opposite does
- CNever — opposites are always positive
- DSometimes — it depends whether the number is a whole number
✏️ Workspace & Solution Steps -
6 MULTIPLE CHOICE
Badwater Basin is 86 meters below sea level, and sea level is 0. Which integer represents that elevation?
- A-86
- B86
- C0
- D-68
✏️ Workspace & Solution Steps -
7 MULTIPLE CHOICE
In Reykjavik the temperature was -9°C. What is the opposite of -9?
- A9
- B-9
- C0
- D-18
✏️ Workspace & Solution Steps -
8 MULTIPLE CHOICE
What is the opposite of 0?
- A0
- BA number written -0, which is less than 0
- CEvery negative number
- DZero has no opposite
✏️ Workspace & Solution Steps
-
9 OPEN RESPONSE
Describe two different real-world situations that use negative integers. For each one, tell exactly what 0 means in that situation, write one negative integer it could produce, and explain what the opposite of that integer would mean in the same situation.
✏️ Mathematical Justification & Response
Writing Task: Justify why your mathematical solution is accurate and complete.