Integers Introduction — Answer Key
Part A: Fix the Sentence
Each sentence has an error. Rewrite it correctly on the line.
1. Fix the sentence:
The opposite of -8 is also -8 because they look the same on paper.
Corrected: The opposite of -8 is 8 because opposites are the same distance from zero.
Opposite integers share the same distance from zero but have different signs.
2. Fix the sentence:
Starting at 0 and moving 4 left lands you on positive 4 on the number line.
Corrected: Starting at 0 and moving 4 left lands you on -4 on the number line.
Leftward motion from zero produces negative integers, not positive ones.
3. Fix the sentence:
The integer 0 has an opposite that equals positive 1 on every number line.
Corrected: The integer 0 is its own opposite because zero has no sign or distance.
Because 0 is neither positive nor negative, it acts as its own opposite.
Part B: Fill in the Blank
Write the missing word or number on each line.
1. The opposite of 7 is -7 on a number line.
Opposites differ only in sign, so 7 maps to -7 across zero.
2. Starting at 0 and moving 3 units right lands on 3.
Moving right from zero by 3 units produces the positive integer 3.
3. Starting at 2 and moving 5 units left lands on -3.
From 2, moving 5 left gives 2 minus 5, which equals -3.
4. The opposite of -10 is 10 on the integer line.
Because -10 is ten units left of zero, its opposite sits ten units right.
Part C: Short Answer
Answer each question in one or two complete sentences.
1. Explain how to find the opposite of any integer using a number line.
Sample answer: Locate the integer, then find the point the same distance from zero on the other side. That point is the opposite.
Opposites are reflections across zero, so distance is preserved while sign changes.
2. Describe how to add 4 plus -6 by moving on a number line.
Sample answer: Start at 4, then move 6 units left because -6 is negative. You land on -2, the sum.
Direction of movement matches the sign, so combining gives the correct sum -2.