53
Solving word problems
Textbook: Part 2, lesson 53, pp. 43–45
GoalSolve word and geometry problems with division, using diagrams and several steps.
New words
diagram · sxemayield · hosildorlikarea · yuzastep · bosqich
Explanation
In a multi-step problem we first draw a diagram and decide what we can find. “So many times more” means multiply, “so many times fewer” means divide. The area of a field is length × width. We use the result of each step in the next one.
Worked examples
The harvest grew 3 times and became 18 600 kg. Before it was 18 600 : 3 = 6 200 kg.
A field is 250 m × 120 m: area 250 × 120 = 30 000 m². At 20 g per m²: 30 000 × 20 = 600 000 g.
Class activity
“The diagram is the key”: groups draw a diagram for a problem, and another group writes an expression from the diagram and solves it.
Practice
1
3 600 kg of tomatoes are packed in crates of 90 kg each. How many crates are needed?
40
2
A field is 250 m long and 120 m wide. If 20 g of fertiliser is used per square metre, how many grams are needed for the whole field?
600000
3
The cotton harvest grew 3 times and became 18 600 kg. What was it before, in kg?
6200
4
On day one 1 200 kg of apples were picked. On day two 4 times less than on day one, on day three 3 times more than on day two. How many kg in total over the three days?
2400