Year 7 - Maths
Subtraction of positive and negative integers
Arithmetic procedures with integers and decimals
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Study Guides
This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils develop their ability and efficacy with the four operations including more complicated and challenging calculations involving fractions, decimals and negative numbers. This leads into an exploration of the priority order of operations.
Lesson Summary
You will learn to use the mathematical structures that underpin subtraction to add and subtract positive and negative integers.
Key Notes
- Any subtraction can be re-written as an equivalent addition.
- Subtracting a postive number is the same as adding a negative number.
- Subtracting a negative number is the same as adding a positive number.
Vocabulary To Learn
- Additive inverse: The additive inverse of a number is a number that, when added to the original number, gives the sum of 0.
- Absolute value: The absolute value of a number is its distance from zero. E.g. 5 and (−5) are both 5 away from zero and so both have an absolute value of 5.
Common Mistakes To Avoid
- Minus and a minus make a plus, 2 negatives make a positive, double negative makes a positive, etc.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Any subtraction can be re-written as an equivalent addition. Subtracting a postive number is the same as adding a negative number.
2. Use this key word in a maths sentence and explain it clearly. 'Additive inverse'
The additive inverse of a number is a number that, when added to the original number, gives the sum of 0. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Minus and a minus make a plus, 2 negatives make a positive, double negative makes a positive, etc. Correction: The use of additive inverses should avoid this common misconception. Be aware that pupils maybe already be familiar with this statement.
More Lessons In This Unit
- Addition of positive and negative integers Study Guide
- Checking and securing understanding of multiplication and division Study Guide
- Checking and securing understanding of negative numbers in context Study Guide
- Checking and securing understanding of written addition and subtraction strategies Study Guide
- Checking understanding of arithmetic procedures with integers and decimals Study Guide
- Dividing with decimals Study Guide
- Multiplication and division where only one value is negative Study Guide
- Multiplication and division where two or more values are negative Study Guide
- Multiplying with decimals Study Guide
- Priority of operations with positive and negative integers and decimals Study Guide
- Priority of operations with positive integers Study Guide
- Problem solving with integers and decimals Study Guide
- Securing understanding of arithmetic procedures with integers and decimals Study Guide
- Simplifying multiplication and division using multiples of 10 Study Guide
- Using the associative, commutative and distributive laws together Study Guide
- Using your calculator efficiently Study Guide
Browse all guides in the Year 7 Maths guide library.