Reddit
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r/mathteachers on Reddit: Subtracting Integers Confusion
May 6, 2024 -
I've been tutoring a 6th grader who shuts down with math when it gets confusing. We've been working on integers for a few weeks, and I felt like she finally seemed to grasp the concept of adding integers, but when it comes to subtracting integers, I don't think I'm explaining it well, or at least not demonstrating what the concept means.
For instance, when we look at 2+(-5), she can imagine the red/yellow integer counters and cancel them out and she can tell me that we're moving 5 spaces to the left on a number line. This leads her to counting up and counting down on her fingers when the integers are within 1-15 spaces of each other. With adding negative integers, I can also get her to tell me which number has a greater absolute value and tell me whether or not the answer will be positive or negative. We ran through 20 or so adding integers problems, and she did well. HOWEVER, when I offered the mental math strategy of 5-2 = 3, but because -5 has a great absolute value, so it's -3, she almost lost it.
Then we get to subtracting integers. She seemed to understand that -4 - 5 = -9 because we're starting with a negative number and subtracting 5, which means moving to the left on a number line, so we end up at -9. But any problem where we subtract a negative number throws her for a loop.
So my questions are two-fold:
What strategies do you use to establish a concrete understanding of subtracting negative integers?
How do you support students with developing mental math/abstract strategies for subtracting negative numbers?
UPDATE:
We had a HUGE breakthrough over the weekend! Thanks to all of your support, I was able to find resources that helped me list a protocol/process for working through each problem. Turning everything into addition and modeling on a number line/with counters at the same time made a huge difference.
I just wanted to say thank you or being to me because as an experienced educator in other fields, I'm expanding my own knowledge of how to scaffold math skills effectively, and no one in this thread criticized me or made me feel like an idiot. I know that's a low bar, but y'all know how it gets. Seriously, thank you all so much!
Top answer 1 of 5
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I watched the screencast linked in the activity description for this Desmos activity years ago and it totally changed how I teach integer operations. I absolutely love the hot air balloon model - it is so concrete and can even extend to multiplication of integers. I strongly recommend it. https://teacher.desmos.com/activitybuilder/custom/5efe58da277abd3653440339
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Kill off double signs. You can combine any two negative signs into a positive sign and if there are multiple signs you can get rid of any extra positive signs, keep doing this until you only have one sign. I like to give practice: 2+--+--+++-+--5(kill off pluses) 2 -- -- -- -5 (then combine 2 minuses into a plus) 2 + + + -5 (then kill off pluses) 2 - 5 Then I like to add the + sign in front of the lead integer. +2 -5 Then I like to think of them as actions. +2 and -5 "So let's say you have a bunch of Pokemon cards (candy, dollars, whatever) On Tuesday your friend Sahaj comes and gives you 2 Pokemon cards, then he takes 5 Pokemon cards from you... After Sahaj's visit, do you have more or less cards? Less! Great, your answer is negative? How many less? 3! That's right. Your answer is negative 3!" Practice each of these seperate until they get it. Also works great leading into algebra simplifying. Once they start thinking of an arithmetic list as a series of things happening it's easy. Give you 2 things, then I take 5 things. The kid will know he has lost three things. Same with -3-5 I take 3 things then I take 5 things. What was the net outcome? Pretty simple, I took 8 things.
Mathnasium
mathnasium.com › math-centers › castlehills › news › subtracting-integers
Subtracting Integers – Kid-Friendly Guide, Rules & Examples
December 4, 2025 - Adding integers: If the signs are the same, add and keep the sign. If different, subtract and keep the sign of the larger absolute value. Subtracting integers: Convert to addition by taking the opposite of the second number, then use addition rules.
Math question, so if I’m adding two numbers with one of each sign, do I always subtract?
Substraction by definition is adding negative number. Definition of substrsction is: a-b = x if and only if a+c=x where c is such number that b+c=0. Simmilary a/b= a • b ⁻¹ More on reddit.com
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June 17, 2023Subtracting Integers Confusion
I watched the screencast linked in the activity description for this Desmos activity years ago and it totally changed how I teach integer operations. I absolutely love the hot air balloon model - it is so concrete and can even extend to multiplication of integers. I strongly recommend it. https://teacher.desmos.com/activitybuilder/custom/5efe58da277abd3653440339 More on reddit.com
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May 6, 2024Can someone explain how subtracting integers work?
When you add, you go forward (right) on the number line. When you subtract, you go backwards (left) on the number line. 8-3: start at 8, move 3 steps backwards, you end up at 5. The number line is particularly useful for negative numbers. On the number line, there is nothing special about negative numbers, they're just a bit farther to the left. Addition and subtraction work the same, you take steps forwards or back. I think that answers your question, but if you're asking about the algorithm for subtracting numbers with multiple digits, where you put the numbers on top of each other and sometimes borrow a 1 from the next digit up, you can think of it as doing exactly the same thing that you do when you add numbers with multiple digits. You split the number up into groups. Theres the ones place, tens place, hundreds place. You then combine each of the groups one-by-one. Sometimes in addition you have to "carry the 1". You have too much in one group, so you have to put it in the next group. In subtraction you do the same thing in reverse. Sometimes you dont have enough in one group to do the subtraction. Instead of moving 1 up to the next group, you have to move a 1 down to help you have enough for subtraction. More on reddit.com
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May 13, 2025(Addition & subtraction of integers) can someone tell me what the name of this symbol is?
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January 17, 2024Videos
03:20
Subtracting Integers | How to Subtract Positive and Negative Integers ...
11:16
Subtracting Integers - YouTube
Subtracting Integers Explained | How to Subtract Integers | Math ...
How to Add, Subtract, Multiply, and Divide Integers | A Review ...
00:58
Subtracting Integers | How to Subtract Integers | Math with Mr. ...
Thelawsonacademy
thelawsonacademy.org › adding-subtracting-integers
Adding & Subtracting Integers | The Lawson Academy
It seems daunting to add integers, but there are two laws that will work with any issue with addition. same signs = add the numbers, and keep the same sign (Ex: 3 + 2 = 5 or -3 + -2 = -5) different signs = subtract the numbers, and keep the sign of the bigger number (Ex: -3 + 2 = -1 or 3 + -2 = 1)
Davenport University
davenport.libguides.com › math-skills-overview › basic-operations › different-signs
Adding Integers with Different Signs - Math Skills Overview Guide - Library Guides at Davenport University
Different Signs - Subtract the smaller absolute value from the larger absolute value and give the answer the same sign as the number with the larger absolute value · Subtracting Integers - Same as adding the opposite of that integer number. A general example to help you recognize patterns ...
Cuemath
cuemath.com › numbers › subtracting-integers
Subtracting Integers - Rules, Steps, Examples
If both integers are negative, then to subtract them, we will first write it as an addition fact. Then, we find the difference between their absolute values and attach the sign of the number with the greater absolute value with the result. For example, let us subtract -45 from -23.
CK-12 Foundation
ck12.org › all subjects › cbse math › subtract integers › what is the rule for subtracting integers with different signs?
Flexi answers - What is the rule for subtracting integers with different signs? | CK-12 Foundation
September 11, 2025 - To add and subtract integers, we can use the following rules Addition: - If the signs are the same, add the absolute values and keep the sign the same. If the signs are different, subtract the smaller absolute value from the larger one and keep the sign of the larger absolute value.
YouTube
youtube.com › watch
Adding and Subtracting Integers: A Step-By-Step Review ...
Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube.
Math Answers
math.answers.com › basic-math › What_is_the_rule_for_subtracting_integers_with_the_same_signs
What is the rule for subtracting integers with the same signs? - Answers
divide them or multiply then put a negative because to different signs make a negative to of the same signs make a positive · Multiply two integers disregarding the signs. Then if the signs are the same, the answer is positive and if the signs ...
Mathnasium
mathnasium.com › math-centers › litchfieldpark › news › subtract-positive-negative-integers
How to Subtract Positive and Negative Integers?
June 12, 2025 - Use the sign of the number with the larger absolute value. Since 9 is bigger and it came from –9, the answer is –6. ... Think of it like this: You’re 9 floors below ground level in a building (–9). If you go up 3 floors (+3), you’re ...
Facebook
facebook.com › groups › 121644125187853 › posts › 293289668023297
Subtracting Integers: Change Sign for Negative
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ChiliMath
chilimath.com › home › lessons › introductory algebra › integer subtraction
Subtraction of Integers | ChiliMath
September 27, 2024 - Step 1: Transform the subtraction of integers problem into addition of integers problem. Here’s how: First, keep the first number (known as the minuend). Second, change the operation from subtraction to addition. Third, get the opposite sign of the second number (known as the subtrahend) Finally, proceed with the regular addition of integers.
Virtual Nerd
virtualnerd.com › pre-algebra › algebra-tools › add-subtract-integers
Adding and Subtracting Integers | Pre-Algebra | The Tools of Algebra | Virtual Nerd
In this tutorial, see how to use a number line to subtract integers with the same sign and ones with opposite signs.
Reddit
reddit.com › r/mathhelp › math question, so if i’m adding two numbers with one of each sign, do i always subtract?
r/MathHelp on Reddit: Math question, so if I’m adding two numbers with one of each sign, do I always subtract?
June 17, 2023 -
So like for example 15 + (-35) I would actually subtract to get the answer? Do I ever actually add when there’s a negative + a positive? Like would -15 + 35 also be subtracting? Or is it whatever the bigger number that’s the type of problem I do so if the - is on the smaller number I would add? I’m not the best at math lol so the littlest thing’s confuse me!
Study.com
study.com › skill › practice › subtracting-integers-with-opposite-signs-questions.html
Subtracting Integers with Opposite Signs Practice
Take online courses on Study.com that are fun and engaging. Pass exams to earn real college credit. Research schools and degrees to further your education.
Khan Academy
khanacademy.org › math › cc-seventh-grade-math › cc-7th-negative-numbers-add-and-subtract
Integers: addition and subtraction | 7th grade math
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CalculatorSoup
calculatorsoup.com › calculators › math › adding-and-subtracting-integers-calculator.php
Calculator to Add and Subtract Integers Showing the Work
For more complex math equations ... and add the numbers. ... If signs are different subtract the smaller number from the larger number and keep the sign of the larger number....
Pinterest
pinterest.com › pin › subtraction--796081671625869605
Subtraction
July 31, 2020 - When autocomplete results are available use up and down arrows to review and enter to select. Touch device users, explore by touch or with swipe gestures. ... When subtracting 2 signed numbers, add the opposite of the subtrahend.
Quora
quora.com › How-do-we-add-and-subtract-numbers-with-opposite-signs
How do we add and subtract numbers with opposite signs? - Quora
Answer (1 of 4): tl;dr The general rules for adding and subtracting two numbers of opposite sign a and b are: a+(-b)=a-b and a-(-b)=a+b Ordered Pairs When we talk about signs we bring negative numbers into the mix. As Alan Bustany points out when talking about negative numbers it’s often he...
BYJUS
byjus.com › maths › addition-subtraction-integers
Properties of Addition and Subtraction of Integers
July 5, 2022 - The rules to subtract integers are given here with examples: -2 – 3 = -5 2 – (-3) = 5 2 – 3 = -1 3 – 2 = 1 ... Rules for the multiplication of integers are different from addition and subtraction rules. Two like signs when multiplied, they result in a positive sign Two unlike signs when multiplied, result in a negative sign.
Answers
math.answers.com › math-and-arithmetic › How_do_you_subtract_integers_like_and_unlike_sign
How do you subtract integers like and unlike sign? - Answers
September 20, 2023 - If both integers have the same ... integers have different signs, subtract the smaller absolute value from the larger one and take the sign of the integer with the larger absolute value....