Lesson 7.1Explore Integers and Their Opposites
Start hereWords, worked example, and sentence starters
Learning target I can use integers to represent quantities in everyday life, explain what 0 means in each situation, and name the opposite of an integer on the number line.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| IntegerSpanish: Número entero | The counting numbers, their opposites, and 0. | −9, −1, 0, 6, 230 |
| OppositeSpanish: Opuesto | A number that is the same distance from 0 as another number, but on the other side of 0. | −6 and 6 are opposites |
| Negative numberSpanish: Número negativo | A number less than 0, written with a − sign. On a number line it sits to the left of 0. | −9 is read negative nine |
| Positive numberSpanish: Número positivo | A number greater than 0. On a number line it sits to the right of 0. | 6, 19, 230 |
| Number lineSpanish: Recta numérica | A straight line where numbers are placed in order. It extends to the left of 0 to show values less than 0. | left is less, right is more |
| Opposite of the oppositeSpanish: Opuesto del opuesto | Taking the opposite twice brings you back to the first number. | −(−6) = 6 |
How it worksWorked examplewriting an integer and naming its opposite
These numbers are not on your problems. The steps are. Follow them with your own numbers.
A submarine sits 47 meters below the surface of the water. Write an integer for its depth, then name the opposite.
- Decide the direction. Below the surface is less than 0, so the integer is negative.
- Write the integer with a negative sign. depth = −47
- The opposite sits the same distance from 0 on the other side. 47
- Check on a number line: one point is left of 0, one is right, both 47 units away.
Answer: The depth is −47 meters and its opposite is 47.
Now you trySame steps, your turn
The steps are the same as the worked example. The numbers are yours. Do the work.
A drone hovers 26 meters above the ground. Write an integer for its height, then name the opposite.
- Decide the direction. Above the ground is than 0, so the sign is .
- Write the integer. height =
- The opposite sits on the side of 0. opposite =
- Check on a number line: both points are units from 0.
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- The integer represents .
- Zero stands for in this situation.
- The opposite of is because .
- On the number line, sits units to the of 0.
Word bank integeroppositenegativepositivenumber linezerodistanceabovebelowleftrightsign
Watch outA common mistake
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.
Lesson 7.1Explore Integers and Their Opposites
Version ASupported practice
Learning target I can use integers to represent quantities in everyday life, explain what 0 means in each situation, and name the opposite of an integer on the number line.
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1Complete the table. Show how you found each value.
Write the integer that represents each situation. Remember to decide what 0 means first.
Situation Integer A football play with a 12-yard loss A hiker 250 meters above sea level 7 degrees below zero A submarine resting at the surface of the water Hint Each row describes a quantity measured from a starting point. That starting point is 0.
Show your work -
2Write the name of the correct group on each line.
Sort each integer by which side of 0 it sits on when you graph it on a number line.
- -86
- 9
- -9
- 21
- -3
- 250
Hint Look only at whether a − sign is in front of the number.
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3Circle the letter of the best answer. Show how you know.
Badwater Basin is 86 meters below sea level, and sea level is 0. Which integer represents that elevation?
- A-86
- B-68
- C0
- D86
Hint Sea level is 0. Is 'below sea level' more than 0 or less than 0?
Show your work -
4Circle the letter of the best answer. Show how you know.
In Reykjavik the temperature was -9°C. What is the opposite of -9?
- A-18
- B-9
- C0
- D9
Hint 'Opposite' means the same distance from 0, but on the other side of 0.
Show your work -
5Circle the letter of the best answer. Show how you know.
What is the opposite of 0?
- AA number written -0, which is less than 0
- BEvery negative number
- CZero has no opposite
- D0
Hint The opposite of a number is the same distance from 0 on the other side.
Show your work
-
6Find the mistake. Explain it, then show the correct work.
Spot the Mistake: The Opposite of -7
- 1ProblemName the opposite of -7.
- 2Student thinkingThe number starts out negative, and taking the opposite of a negative number keeps it negative, so the answer stays on the left side of 0.
- 3Student answerThe opposite of -7 is -7.
Which step has the mistake? Explain what went wrong, then show the correct work.
Hint What does the word 'opposite' require about which side of 0 a number is on?
Correct workCorrect answer:
Explain your thinkingHow did you decide what 0 meant in each situation, and how did that decide the sign of the integer?
Sentence starter In this situation 0 means ___. The quantity is ___ zero, so I represent it with a ___ integer, which is ___.
Lesson 7.1Explore Integers and Their Opposites
Version BCore practice
Learning target I can use integers to represent quantities in everyday life, explain what 0 means in each situation, and name the opposite of an integer on the number line.
-
1Complete the table. Show how you found each value.
Write the opposite of each integer.
Integer Opposite -15 8 0 -100 Show your work -
2Mark and label each value on the number line.
Graph these integers: -9, 9, 0, -4, 6
Show your thinking -
3Circle the letter of the best answer. Show how you know.
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
Show your work
-
4Circle the letter of the best answer. Show how you know.
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
Show your work -
5Circle the letter of the best answer. Show how you know.
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
Show your work
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6Find the mistake. Explain it, then show the correct work.
Spot the Mistake: Reykjavik's Temperature Swing
- 1ProblemAt 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 thinkingThe 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 answerThe temperature at 2 p.m. was -24°C.
Which step has the mistake? Explain what went wrong, then show the correct work.
Correct workCorrect answer:
Explain your thinkingHow did you decide what 0 meant in each situation, and how did that decide the sign of the integer?
Lesson 7.1Explore Integers and Their Opposites
ChallengeExtension
Learning target I can use integers to represent quantities in everyday life, explain what 0 means in each situation, and name the opposite of an integer on the number line.
-
1Write the name of the correct group on each line.
Order these integers from LEAST to GREATEST.
- 9
- -86
- 0
- -9
- 21
- -3
-
2Circle the letter of the best answer. Show how you know.
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.?
- A-12°C and 12°C
- B0°C and 12°C
- C12°C and -12°C
- D12°C and 24°C
Show your work -
3Circle the letter of the best answer. Show how you know.
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?
- A8 yards past the line of scrimmage
- B12 yards past the line of scrimmage
- C18 yards past the line of scrimmage
- D38 yards past the line of scrimmage
Show your work
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4Answer in complete sentences.
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.
Write your answer