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7th grade
Course: 7th grade > Unit 3
Lesson 4: Subtracting negative numbers fluentlySubtracting negative numbers review
Review the basic of subtracting negative numbers and try some practice problems.
Subtracting negative numbers
Subtracting a number is the same as adding the opposite of the number.
Let's look at two examples:
Note: In both examples, we change subtraction to addition and changed the sign of the second number to the opposite sign.
Want to know why this works? Check out this video.
Once we have an addition problem, we can solve.
Example 1: negative minus negative
Lets subtract minus, 5, minus, left parenthesis, minus, 6, right parenthesis.
Step 1: Rewrite as an addition problem
Step 2: Start at the first number in the addition problem, in this case minus, 5:
Step 3: Move 6 places to the right. We move 6 to the right because adding positive 6 increases our number by 6.
minus, 5, plus, 6 takes us to 1 on the number line.
Example 2: negative minus positive
Lets subtract minus, 4, minus, 7.
Step 1: Rewrite as an addition problem
Step 2: Start at the first number in the addition problem, in this case minus, 4:
Step 3: Move 7 places to the left. We move 7 to the left because adding negative 7 decreases our number by 7.
minus, 4, plus, left parenthesis, minus, 7, right parenthesis takes us to minus, 11 on the number line.
Want to learn more about subtracting negative numbers? Check out this video.
Want to join the conversation?
- why does it say subtract when you have to add(266 votes)
- Because two negatives equal a positive in a subtraction when it's next to each other. 3-(-6)=9=3+6=9(113 votes)
- Negative minus a positive is a negative?(72 votes)
- Yes, subtracting a positive always makes the number smaller.(53 votes)
- So basically 2 negatives make a positive?(56 votes)
- You could be mistaking this for a multiplication problem. negative * negative = positive but in addition negative + negative = negative.(11 votes)
- Give me 10 votes for Moon badge please(39 votes)
- i will still vote(21 votes)
- may people please press the upvote button for i am seeking a badge(43 votes)
- Say goodbye! Never gonna tell a lie!(1 vote)
- May 10 people consider pressing the upvote button as i pursue an educational moon badge(37 votes)
- pls give me ten votes for the moon badge(39 votes)
- So, correct me anyone if I'm wrong. So let's say I have
-4-(-4), wouldn't equal 0? Because instead of me subrtracting with -4, I have to add it. So, would it be 0 instead of -8?(31 votes)- Yes that is correct.(6 votes)
- can 10 people please vote me i want the moon badge to(25 votes)