lesson
The denominator names the part
1 · Learn
Rewrite unlike fractions with equal denominators before adding or subtracting. Add the counts of parts, not their names. Mixed numbers can be converted into improper fractions before calculation.
Estimate whether the answer should be below or above one. Simplifying afterwards makes the value easier to recognise but must not change it.
2 · Worked example
3/4 + 2/3 = 9/12 + 8/12 = 17/12 = 1 5/12. For 2 1/6 - 3/4, use 26/12 - 9/12 = 17/12.
3 · Your turn
Find 5/6 - 3/8 and 1 3/4 + 2/5.
Check your answer
20/24 - 9/24 = 11/24. Also 35/20 + 8/20 = 43/20 = 2 3/20.
4 · Apply your learning
Use a common whole to explain why adding denominators would give the wrong-sized parts.
Adult guidance and safety
Ask the learner to explain the method and check it using a different representation. Supply place-value grids, fraction strips, accurate diagrams and measuring tools where needed. These examples need varied practice; a short correct answer alone does not establish fluency.
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Check a calculation · Year 5 onward
Use this only when your teacher or adult allows a calculator for the task. Show your thinking first. It does not replace mental or written arithmetic and does not mark your lesson answer.
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