Practice 1
Answer and teaching response
6 · Each cup has three third-cup servings; two cups give six.
Treat the serving size as the repeated unit, count how many fit in the supply and keep that count distinct from the amount per serving.
Get the student and teacher materialsLearning goal: Produce a serving plan that names total supply, amount per serving and number of servings, with a multiplication check.
You will need: Paper strips and a pencil. Use cups as a stated mathematical unit; the invented quantities do not require handling food or liquid.
A supply contains 3 cups. Each serving must contain exactly 1/4 cup. How many servings can be made?
12 servings. Each cup contains four quarter-cup units, so three cups contain twelve such units.
A learner might say: Divide 3 by 4 to get 3/4 of a serving.
Four is the number of quarter-cup units in one whole cup, not the recipient count. Draw those units in each cup and count how often the fixed serving size fits.
Try the first three tasks with the worked model. Try the final task without help. Enter a number, fraction or mixed number, such as 3/4 or 1 1/4. The number check does not assess your drawing or explanation.
6 · Each cup has three third-cup servings; two cups give six.
10 · Five whole cups contain ten half-cup units.
8 · Eight equal eighth-cup portions fill the whole cup.
24 · Four groups of six servings give twenty-four; 24 × 1/6 cup = 4 cups.
Keep the 3-cup supply but change each serving from 1/4 cup to 1/2 cup. What happens to the serving count, and why?
It changes from 12 to 6. Each new serving combines two of the earlier quarter-cup portions, so twice the serving size produces half as many servings from the same supply.
Look for:
If the idea is not secure: Draw one whole cup first and count its unit-fraction portions before repeating the pattern for additional cups.
If the learner is ready: For a fixed supply of 2 cups, compare half-, third- and quarter-cup portions: the counts are 4, 6 and 8. Explain the pattern in units.
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