COMPARING WEIGHT
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CLASS: Basic 3
SUBJECT: Mathematics
TOPIC: Weight
CONTENT:
Weight describes how heavy or light an object is. We can compare objects by using their weight because, some objects are heavy while some objects are light.
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COMPARING WEIGHT
- A bag of sugar weighs more than a loaf of bread.
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An eraser weighs less than a cup.
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Your mathematics text book weighs more than your exercise book.
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We can measure or know the weight of an object by using weighing scales. Examples of different weighing scales are:
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All of these are used to measure the weight of different objects.
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STANDARD UNITS OF WEIGHT
(i) The kilogram (kg) is used as a unit when we weigh heavy objects like bag of rice, bag of cement, etc.
(ii) The gram (g) is used when we weigh lighter objects like pencils, rulers, etc.
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Relationship Between Grams (g) and Kilograms (kg).
When we have 1000g = 1kg (that is 1000grams is the same as 1kilogram)
We can change grams to kilograms and change kilograms to grams.
Know that: When you want to change grams to kilograms you divide by 1000.
Example: change 2000g to kilogram
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2000 ÷ 1000 = 2kg
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Also know that: When you want change kilograms to grams you multiply by 1000.
Examples: (i) change 2kg to grams.
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2 × 1000 = 2000g
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(ii) Change 1/4kg to grams.
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1/4 × 1000
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1 × 1000/4
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1000/4 = 250g
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Answer these questions:
Compare these objects by using (more than or less than)
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A bottle of water weighs ______________ An empty bottle.
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A pineapple weighs ______________ an orange.
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A hen weighs ____________ a dog.
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An exercise book weighs ____________ your school bag.
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Change 4000g to kilograms
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Change 7kg to grams
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Change 1/2 kg to grams
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Change 2500g to kilograms.