Lesson plan by OtisamLMS · OtisamLMS
| Subject | Core Mathematics · SHS |
| Year | SHS 1 |
| Term / week | Term 1 · Week 4 |
| Lessons this week | 3 × 60 minutes |
| Class size | 45 |
| Strand | Number |
| Sub-strand | Fractions, decimals and percentages |
| Content standard | Learners carry out the four operations on fractions and use them to solve everyday problems. |
| Learning indicators | Find the lowest common multiple of two or three denominators Add and subtract fractions and mixed numbers with unlike denominators Check an answer by estimating with whole numbers |
| Core competencies | Critical thinking and problem solving Communication and collaboration Personal development (perseverance) |
| Key words | numerator, denominator, equivalent fraction, lowest common multiple, mixed number, improper fraction |
| Resources | Paper strips (one A4 sheet per pair) A market price list written on the board Exercise books and coloured pens |
| Phase | Teacher and learner activities |
| 1. Starter | Write 1/2 + 1/3 on the board and ask three learners to give a quick guess. Most will say 2/5. Fold a paper strip into halves and another into thirds and hold them side by side: is 2/5 really bigger than 1/2? Let pairs argue for two minutes before you move on. |
| 2. Main activities | 1. Pairs fold strips into halves, thirds and sixths and shade 1/2 and 1/3 on the sixths strip. They record 1/2 = 3/6 and 1/3 = 2/6, so the sum is 5/6. 2. Ask: why did sixths work? Draw out that 6 is a multiple of both 2 and 3. Introduce the lowest common multiple and list multiples to find it for 4 and 6, then 3, 4 and 8. 3. Model two examples on the board, saying each step aloud: find the LCM, rewrite each fraction, add or subtract the numerators, simplify. 4. Mixed numbers: a trader sells 2 3/4 kg of rice in the morning and 1 2/3 kg in the afternoon. Groups solve it two ways (whole numbers first, then improper fractions) and compare. 5. Learners work through eight graded questions. Circulate, and pull a small group to the front table for extra modelling if needed. |
| 3. Reflection | Learners write one sentence on a slip: 'The mistake I will not make again is…'. Read a few aloud. Close by returning to 1/2 + 1/3 and asking a learner to explain why 2/5 was wrong. |
Exit questions: (a) 3/4 + 1/6 (b) 5/8 − 1/3 (c) 3 1/2 − 1 4/5. A learner who gets (c) right has met all three indicators. Mark in class; note who needs support in the next lesson.
Support: keep the folded strips on the desk and limit the work to denominators below 12.
Extension: write a word problem that needs 2/3 + 3/5 and swap it with a partner.
Find two prices at home or in the market that use halves or quarters (e.g. half a bag of gari) and write a subtraction problem from them.
Learners often add the denominators. The paper strips in the starter are worth the time; do not skip them.
Printed from https://otisam.com/lesson-plans/adding-and-subtracting-fractions-with-unlike-denominators