Modelling with multiplication and fractions
Model real-world problems involving multiplication, area, fractions, and unit conversion by choosing appropriate representations and interpreting mathematical results in context
What a learner can do afterwards
- Model a tiling/area problem with an array and write the corresponding multiplication
- Represent a recipe-scaling problem as a fraction calculation and interpret the answer in grams
- Use a bar model to set up a unit conversion problem (metres to centimetres)
The lesson
Some real-life problems need more than one type of maths. You might multiply to find an area, use a fraction to scale a recipe, or convert units like metres to centimetres. The trick is picking the right tool, then checking that your answer makes sense for the real situation.
A cookie recipe uses 200 grams of sugar. Mia wants to make half the recipe. She works out 1/2 × 200 = 100. She needs 100 grams of sugar.
A garden path is 4 metres long. Sam wants to know the length in centimetres, so he draws a bar split into 4 equal metre-sized parts. Each part is 100 centimetres, so he works out 4 × 100 = 400. The path is 400 centimetres long.
When you get a final number, check what it means for the real problem: is it tiles, grams, or centimetres? Matching the number to its units and story tells you the answer makes sense.
Pick arrays for area, fractions for scaling, and bar models for units, then check your answer fits the real problem.
Watch it
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.