Subtracting Integers Worksheet: Rewriting as Addition
Subtracting integers can feel tricky at first, especially when negatives and parentheses show up. The good news is that there is a reliable strategy that works every time: rewrite subtraction as addition. This worksheet gives students focused practice using that strategy, step by step, until it becomes automatic.
When students learn integer subtraction, the biggest stumbling block is usually the sign change. Many students know how to add and subtract positive numbers, but they freeze when they see “minus a negative” or a subtraction sign followed by parentheses. That is exactly where the Keep-Change-Change method helps. It turns subtraction into a familiar addition problem so students can focus on number sense instead of symbol confusion.
This printable worksheet is designed for grades 6–8 and pre-algebra classes. It includes three structured sections so students can build confidence in layers: first rewriting only, then rewriting and simplifying, and finally a mixed set that requires careful attention to signs.
The Big Idea: Subtraction Becomes Addition of the Opposite
A simple rule powers the entire skill:
Subtracting an integer is the same as adding its opposite.
That means instead of trying to “do subtraction with negatives,” students can convert the problem into addition, which is more consistent and easier to check.
A quick way to remember the conversion is:
Keep – Change – Change
-
Keep the first number the same
-
Change subtraction to addition
-
Change the second number to its opposite
Once the expression is rewritten, students simplify using integer addition rules.
How this worksheet is organized (and why it works)
This resource is built to reduce common mistakes and help students practice with purpose.
Section A: Rewrite as addition (do not simplify)
Students practice the conversion only. This is important because many errors happen before any math even starts. In this section, students learn to:
-
keep the first integer unchanged
-
switch subtraction to addition
-
flip the sign of the second integer
Because the directions say “do not simplify,” students can focus on the structure of the rewrite.
Section B: Rewrite, then simplify to a final integer
Now students do both steps: convert and compute. This section reinforces that rewriting is not the final answer — it is the setup that leads to the correct result.
Section C: Mixed practice with close sign-checking
This section includes more variety, including negatives and parentheses, so students must stay careful. It is great for catching the classic errors:
-
forgetting to flip the sign of the second integer
-
dropping the negative sign inside parentheses
-
treating “minus a negative” like “minus a positive”
Tips for teaching (or reviewing) this skill
If students are still making sign mistakes, try these quick reminders:
-
Point to the subtraction sign first. If there is no subtraction sign, there is nothing to “keep-change-change.”
-
Circle the second integer. That is the number whose sign changes.
-
Say it out loud: “I’m adding the opposite.”
-
Use parentheses when rewriting. Writing something like “+ (negative six)” can prevent sign slips.
A nice checkpoint after rewriting is to ask:
“Does my new expression make sense as addition?”
If yes, the student can move on to simplifying with confidence.
When to use this worksheet
This worksheet works well for:
-
introducing integer subtraction after integer addition
-
warm-ups and spiral review
-
reteach groups and intervention
-
homework or independent practice
-
a quick quiz-style check (choose one section)
Because it includes an answer key, it is easy for students to self-check or for teachers to grade quickly.
