108
Quantities: length, mass, capacity
Textbook Part 3, pp. 70–71
GoalUnderstand that a quantity is a property of an object that can be measured; choose the right unit.
New words
quantity (measurable property) · kattalikunit of measure · o‘lchov birligicooking pot · qozon
Explanation
A property of an object that can be measured is called a quantity. We know three: length (cm, dm, m), mass (kg) and capacity (l). Colour or shape are not quantities — they cannot be measured with a number.
Worked examples
Plov in a 10-litre pot: 2 kg meat, 2 kg carrots, 2 kg rice, 1 kg onion → 2 + 2 + 2 + 1 = 7 kg of food.
A watermelon’s mass is a quantity (8 kg); its colour is not.
Class activity
“Three boxes” labelled length, mass and capacity. Children sort cards (5 cm, 3 kg, 2 l, 7 dm…) into the right box.
Practice
1
Which quantity does each unit measure: kg, l, cm?
kg — mass, l — capacity, cm — length
2
2 kg + 2 kg + 2 kg + 1 kg = ?
7 kg
3
Not a quantity: length, colour, mass?
Colour
4
Find the unknown: _ + 15 = 48
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