Practice Set · Part 1
Understand Absolute Value of Rational Numbers
Pick up where we left off
Where we left off
Our goal: I can find the absolute value of a rational number — an integer, fraction, or decimal — as its distance from zero, explain why the method works, and use it on a problem I have not seen before.
The big idea: Absolute value is a distance from zero, so it is never negative. It works the same for fractions and decimals as it does for whole numbers — and you can say why it is true, and where it would stop being true.
Model to copy — Watch me
- I want to find the absolute value of -6, written |-6|.
- I find -6 on the number line. It sits 6 steps to the left of zero.
- Distance does not care about direction, so -6 is 6 units from zero.
- So |-6| = 6. Even though -6 is negative, its absolute value is positive 6.
Start here
You did these with your group. Now do them on your own — the model above is yours to copy.
- 1
Same stepsFinish what the group started. Use the model above, step for step.
Try it together — then prove it: Now let's find |3|. Where is 3 on the number line? It is 3 steps to the right of zero. How far is it from zero? It is 3 units away. So |3| equals what? It equals 3. Now prove it: say why that move had to work at all — not just that it did.Show your work - 2
Warm restartWhich number sits between 2 and 3 on a number line?
- A2.4
- B3.2
- C−2.5
- D1.9
How do you know?
- 3
Warm restartWhat is the opposite of 3/4?
- A−3/4
- B4/3
- C3/4
- D0
How do you know?
- 4
Warm restartBetween which two integers does −1/2 sit on a number line?
- A−1 and 0
- B0 and 1
- C−2 and −1
- D−1/2 is not on the number line
How do you know?
Practice Set · Part 2
Understand Absolute Value of Rational Numbers
Keep going
You answered these out loud. Now write them.
Answer, then say how you know — the reason is the part that counts.
- 5
Think it throughWhat is |−150|?
- A150
- B−150
- C0
- D300
Why is that the answer?
- 6
Think it throughWhich craft is FARTHER from sea level?
- AThe helicopter, because 200 > 150
- BThe submarine, because −150 < 200
- CThey are the same distance
- DYou cannot compare them
How do you know? Give a second reason as well.
- 7
Think it throughWhich craft is at the LOWER position?
- AThe submarine, because −150 < 200
- BThe helicopter, because 200 > 150
- CThey are equal
- DThe submarine, because 150 < 200
Explain your thinking. What would have to change for a different choice to be right?
- 8
Back to the modelHow does the number line help you see the difference between an integer and its absolute value?
Practice Set · Part 3
Understand Absolute Value of Rational Numbers
Words and reasoning
Word bank · Banco de palabras
Use the words
Fill each blank with a word from the bank.
- The distance of an integer from zero is its ___ ___.
- A whole number or its opposite, like −2, 0, or 5, is an ___.
- A number greater than zero is ___.
- A number less than zero is ___.
Explain the thinking
- 9
Find the mistakeAnother student made this exact mistake in this lesson. Explain why it is wrong, then write what they should have done.
The mistake: A common mistake in Integers and Absolute Value is judging size by the digits alone instead of position on the number line — students think -8 is 'more' than -3 because 8 > 3, when really -8 sits farther left (colder, deeper, or lower) and is actually the SMALLER integer. - 10
Say moreA diver is at -30 feet and a hawk is at +30 feet. How can absolute value help you describe how far each is from sea level?
- 11
Write your ownWrite your own problem about this situation, then solve it and show the answer. The situation: Claire is performing a science experiment with two liquids. The temperatures of the two liquids in Celsius are shown, and she needs to use the beaker with the temperature closer to 0°C.
Show your work
Practice Set · Part 4
Understand Absolute Value of Rational Numbers
Show what you know
Last check
These two come from Lesson 7.2. If they are shaky, that is the lesson to revisit — not this one.
- 12
Show what you knowExplain your thinking — Which integer has an absolute value of 8 and is located to the LEFT of zero on the number line?
- A8
- B-8
- C0
- D-80
Explain your choice.
- 13
From Lesson 7.2Explain your thinking — Which rational number is located between -2 and -3 on the number line?
- A-1.5
- B-2.75
- C-3.5
- D2.5
How do you know?
- 14
From Lesson 7.2Why are rational numbers more useful here than integers alone?
- AThey let the scientist record part-of-a-foot changes like 0.75 and −1.25
- BThey are easier to add
- CIntegers cannot be negative
- DThey make the lake bigger
How do you know?
Be honest — this tells your teacher what to do next
| I can… | Not yet | Getting there | Got it |
|---|---|---|---|
| I can find the absolute value of a rational number — an integer, fraction, or decimal — as its distance from zero, explain why the method works, and use it on a problem I have not seen before. | |||
| I can explain why it works: Absolute value is a distance from zero, so it is never negative… | |||
| I can justify my answer to a skeptic and connect it to a second strategy or representation. |
One question I want to ask my group next time