Lesson 7.3Understand Absolute Value of Rational Numbers
Set B · Version ASecond form · supported practice
Learning target I can find the absolute value of a rational number — an integer, fraction, or decimal — as its distance from zero.
Why This Matters Claire is performing a science experiment with two liquids. The temperatures of the two liquids in Celsius are shown. She needs to use the beaker with the temperature that is closer to 0°C. Which beaker should Claire use?
RememberUnderstand Absolute Value of Rational Numbers
Absolute Value. Formula: |a| = Distance of a from 0 (always ≥ 0) A rational number is any number that can be written as a fraction: integers like -6, fractions like -3/4, and decimals like 2.5 are all rational numbers. The absolute value of a number is how far it is from zero on the number line. Distance is never negative.
- Absolute value represents distance on a number line, never direction.
- Distance is always positive or zero: |-7| = 7 and |7| =
- Context: Magnitude of temperature, debt, elevation regardless of sign
Words: Integer (Número entero)Positive (Positivo)Negative (Negativo)Absolute value (Valor absoluto)Opposite (Opuesto)
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1Circle the letter of the best answer. Show how you know.
What is |−3/4|?
- A0
- B3/4
- C−3/4
- D4/3
Hint Mark −3/4 on a number line between −1 and 0.
Show your work -
2Circle the letter of the best answer. Show how you know.
Which number sits between 2 and 3 on a number line?
- A1.9
- B2.4
- C−2.5
- D3.2
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3Circle the letter of the best answer. Show how you know.
What is the opposite of 3/4?
- A0
- B−3/4
- C3/4
- D4/3
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4Circle the letter of the best answer. Show how you know.
Between which two integers does −1/2 sit on a number line?
- A0 and 1
- B−1 and 0
- C−1/2 is not on the number line
- D−2 and −1
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5Circle the letter of the best answer. Show how you know.
The opposite of a number sits the same distance from 0 but on the…
- Aother side of 0
- Bsame side of 0
- Cexact same point
- Dfar end of the line
Show your work
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6Find the mistake. Explain it, then show the correct work.
The Missing Sign Mistake
- 1ProblemFind the absolute value of -9.
- 2Student's thinkingThe number inside the bars is negative, so I should keep the negative sign in my answer.
- 3Student's answer|-9| = -9
Which step has the mistake? Explain what went wrong, then show the correct work.
Hint Can you walk backward -5 steps? Distance is always zero or positive, no matter which direction you moved.
Correct workCorrect answer:
Explain your thinkingHow does the number line help you see the difference between an integer and its absolute value?
Sentence starter The integer ___ is located ___ units from zero, so its absolute value is ___. Even though ___ is negative, its distance from zero is still ___.
Lesson 7.3Understand Absolute Value of Rational Numbers
Set B · Version BSecond form · core practice
Learning target I can find the absolute value of a rational number — an integer, fraction, or decimal — as its distance from zero.
Why This Matters Claire is performing a science experiment with two liquids. The temperatures of the two liquids in Celsius are shown. She needs to use the beaker with the temperature that is closer to 0°C. Which beaker should Claire use?
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1Circle the letter of the best answer. Show how you know.
A submarine is at -150 meters (below sea level) and a helicopter is at +200 meters (above sea level). A rescue team needs to know how far each is from sea level to plan a mission. What is |−150|?
- A0
- B150
- C−150
- D300
Show your work -
2Circle the letter of the best answer. Show how you know.
A submarine is at -150 meters (below sea level) and a helicopter is at +200 meters (above sea level). A rescue team needs to know how far each is from sea level to plan a mission. Which 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
Show your work -
3Circle the letter of the best answer. Show how you know.
A submarine is at -150 meters (below sea level) and a helicopter is at +200 meters (above sea level). A rescue team needs to know how far each is from sea level to plan a mission. Which craft is at the LOWER position?
- AThe helicopter, because 200 > 150
- BThey are equal
- CThe submarine, because 150 < 200
- DThe submarine, because −150 < 200
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4Circle the letter of the best answer. Show how you know.
On a frosty morning at the mountain cache, the thermometer reads -8 degrees. What is the absolute value of -8?
- A-8
- B0
- C8
- D16
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5Circle the letter of the best answer. Show how you know.
Two treasure sites report their temperatures: -5 degrees F at the Ice Cave and -2 degrees F at the Frozen Dock. Which site is COLDER?
- A-5 degrees F (Ice Cave)
- B-2 degrees F (Frozen Dock)
- CThey are the same
- DNeither is below zero
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6Circle the letter of the best answer. Show how you know.
Captain Vega compares |-12| (a deep cave) and |7| (a hilltop). Which absolute value is GREATER?
- A|7| because 7 is positive
- BThey are equal
- C|-12| = -12, so |7| is greater
- D|-12| because 12 > 7
Show your work