160
Year review
Textbook: Part 4, lesson 149, pp. 72–73
GoalYear review: units of measure and comparing them.
New words
length · uzunlikmass · massavolume · hajmarea · yuz
Explanation
Length – m, km; mass – kg; volume – L and cubic units (cm³, m³); area – square units (cm², m²). Before comparing we change to the same unit: 240 dm = 24 m, so 25 m > 240 dm. 500 m × 2 = 1000 m = 1 km. In problems we tell “share equally” (20 people into 5 tents – 4 in a tent) from “group by size” (5 people in each tent – 4 tents).
Worked examples
34 kg against 8 kg × 4: 8 × 4 = 32 kg, so 34 kg > 32 kg.
The square metre (m²) is a unit of area, the cubic metre (m³) is a unit of volume.
Class activity
“Find the pair”: two sets of cards: quantities (length, mass, volume, area) and units (m, kg, L, m², m³). Children find pairs and attach them to the board. The class corrects wrong pairs.
Practice
1
Which quantity does the square metre (m²) measure?
area
2
Which quantity does the litre measure?
volume
3
How many metres is 240 dm?
24
4
8 kg × 4 = how many kilograms?
32
5
20 people were placed equally in 5 tents. How many people are in one tent?
4
6
20 people were placed 5 to a tent. How many tents were needed?
4
7
(974 − 445 + 71) : 100 × 4 = ?
24