Watch out
Adding denominators.
Scottish National 5 Mathematics
National 5 Maths Fractions
Add, subtract, multiply and divide fractions, including mixed numbers and combined operations.
Formula reference
Check the National 5 rules and formulae linked to this topic.
Which method?
Match exam clues to a suitable method.
Before you start
- Convert mixed numbers to improper fractions.
- Be ready to work exactly without a calculator and show each mathematical step.
- Read the command word, record the units or requested form, and make the final answer match it.
Explanation
Fractions is an assessed part of Scottish National 5 Mathematics in the number area. Add, subtract, multiply and divide fractions, including mixed numbers and combined operations.
Convert mixed numbers to improper fractions.
Use a common denominator for addition or subtraction.
Multiply by the reciprocal for division, then simplify.
The interactive bank below mixes direct skills, reverse questions, interpretation and contextual reasoning rather than repeating one number pattern.
Key formulae and rules
- x = ac/bd
- / = x
Check
Estimate the size of the result, then check that the fraction is in its simplest form.
Exam tip
Show the number rule or multiplier used, retain exact values where requested and round only once at the end.
Worked examples
Worked example 1
Fractions worked example
Calculate 1 −
- 1 =
- − = −
Answer:
Watch out
- Adding denominators.
- Forgetting to invert the second fraction when dividing.