Read the problem once for the situation, then identify the known quantities and the unknown. The relationship between them guides the calculation.
Clarify the quantities
Consider this worked example: 24 children are arranged into 3 equal groups. Ask what 24 counts, what 3 counts, and what the question asks for. Here, 24 is the total number of children, 3 is the number of groups, and the unknown is the number of children in each group.
The Institute of Education Sciences recommends deliberate instruction in word problems to strengthen mathematical understanding and application. [1] Naming the units and the unknown gives the calculation a meaning before symbols are written.
Represent equal groups
Draw three boxes to stand for the groups and distribute 24 marks among them equally. The model should show that every box receives the same number. When the marks are shared evenly, each box has eight.
This arrangement represents 24 ÷ 3 = 8. The answer's unit is children per group. If the question instead asked how many groups of three could be made from 24, the quantities would be related differently even though the same numbers appear.
Choose the operation from the structure
Division fits this example because the total is known, the number of equal groups is known, and the amount in each group is unknown. Multiplication can also describe the relationship once the group size is found: 3 groups of 8 make 24.
Do not rely on a single word as an operation signal. Read the whole situation and decide how the quantities relate. A representation such as equal boxes, a diagram, or objects can make that relationship easier to inspect.
Check the answer against the story
Ask whether eight per group uses all 24 children and makes three equal groups. Multiply 3 by 8 to check that the total returns to 24. Then state the answer with its unit: eight children in each group.
If the answer were eight groups, that would answer a different question. Checking the unit and restating the unknown helps catch answers that are numerically plausible but mismatched to the problem.
Use prompts that leave the reasoning with the learner
A helper can ask what is known, what is missing, and what drawing could show the relationship. Pause after each question so the learner can make the model and choose a calculation. Avoid naming an operation before the quantities are understood.
Teachers may use different diagrams or vocabulary. Match the learner's classroom approach where possible, and ask the teacher for an example model if home practice and school notation seem out of step.
Return to the original example after working out eight children in each of three equal groups. Three groups of eight make twenty-four, so the answer fits the stated total. Ask what the eight counts: children per group, rather than eight groups or eight children altogether. Checking the meaning of the unit is a separate step from calculating a number.
References
Sources for the cited guidance and reported material. Worked examples and practical tools are original to Zolls.
- Institute of Education Sciences. Assisting Students Struggling with Mathematics: Intervention in the Elementary Grades.
