Use and change

Solve problems about use per day ("per day × days") and about change ("before - after") in steps and write the answer.

Guide

In Russian schools (Grade 4, "Word problems", the books of Moro and Peterson) children solve problems about use ("per day" × number of days = total) and about change of an amount: before, taken away or added, after.

Such problems are written in steps with a note: "1) 8 × 5 = 40 (kg) used; 2) 90 − 40 = 50 (kg) left". The answer is written at the end as a full sentence.

Remind the child that the familiar "price × quantity = cost" is the same pattern as "use per day × days = use over all the days".