7.1 Small Group · Group 1
Second Practice Form · Re-Teach, Homework or Retake · Same Standard, New Problems
Integer · Opposite · Procedural Fluency · Real-World Applications
- Counting numbers, their opposites, and 0 are integers. A negative integer is less than zero and is written with a − sign. Opposites are the same distance from 0, but on opposite sides of the number line. We'll walk through a worked example, try one together, then you'll try a few with hints right there when you need them.
- Badwater Basin is 86 meters below sea level, and sea level is defined as 0.
- Below 0 means a negative number, so I write the elevation as −86 meters.
- On a number line, I count 86 units to the LEFT of 0 and mark that point.
- The opposite of −86 is 86. Both are 86 units from 0, just on different sides.
- 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.
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1 MULTIPLE CHOICE
Which statement about 0 is TRUE?
- A0 is an integer, and it is its own opposite
- B0 is a negative integer because it is not positive
- C0 is a positive integer because it has no negative sign
- D0 is not an integer at all
✏️ Workspace & Solution Steps
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2 MULTIPLE CHOICE
Which list of integers is ordered from LEAST to GREATEST?
- A-8, -3, 0, 5
- B-3, -8, 0, 5
- C0, -3, -8, 5
- D5, 0, -3, -8
✏️ Workspace & Solution Steps -
3 MULTIPLE CHOICE
Badwater Basin is at -86 meters. Which elevation is FARTHER below sea level than Badwater Basin?
- A-120 meters
- B-40 meters
- C0 meters
- D86 meters
✏️ Workspace & Solution Steps -
4 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 -
5 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
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6 ERROR ANALYSIS
Spot the Mistake: Reykjavik's Temperature Swing
- 1Problem: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. What was the temperature at 2 p.m.?
- 2Student thinking:The opposite of a temperature should still be a cold temperature, so I keep the negative sign and just make the number bigger. That gives a temperature farther from 0.
- 3Student answer:The temperature at 2 p.m. was -24°C.
Which step contains the error? Explain the mathematical misconception and write the correct calculation below.
✏️ Corrected Mathematical Work & Explanation
Writing Task: Justify why your mathematical solution is accurate and complete.