Students often refer to Class 5 Maths Notes and Chapter 8 Weight and Capacity Class 5 Notes during last-minute revisions.
Class 5 Maths Chapter 8 Notes Weight and Capacity
Class 5 Maths Notes Chapter 8 – Class 5 Weight and Capacity Notes
Weight is a term used to describe how heavy something feels. When we talk about something being heavy, we mean it has a lot of weight. On the other hand, when something is light, it has a very less weight.
To measure how heavy things are, we use different units. For heavier items, we typically use kilograms (kg), and for lighter ones, we use grams (g). We often use a balance that helps us to compare the weights of different objects.
→ Kilogram (kg) is standard unit used to measure weight (or mass) and used for heavier objects.
→ Gram (g) is a smaller unit, used to measure the weight of lighter objects.
→ For very heavy objects, we use quintal and tonne.
→ 1,000 g = 1 kg or 1 kg = 1,000 g
→ 1 g = 1,000 milligram (mg)
→ 100 kg = 1 quintal and 10 quintals = 1 tonne ⇒ 1,000 kg = 1 tonne
→ When adding or subtracting weights, we either:
- convert all values to the same unit (usually grams), or
- add/sub tract kg with kg and g with g
→ Double number lines can help in unit conversions and comparing weights.
→ Millilitres (ml) are used to measure small quantities of liquids.
→ Litres (l) are used for larger quantities.
→ 1000 ml = 11 or 11 = 1000 ml
→ When adding or subtracting capacities, we either:
- convert all values to the same unit (usually millilitres), or
- add/subtract l with l and ml with ml
→ Double number lines are useful for converting units and comparing capacities.
Weight Measurements
→ Kilogram (kg) Standard unit for measuring larger weights.
→ Gram (g) Used for smaller weights.
→ 1 kilogram (kg) = 1000 grams (g).
→ Milligram (mg) Used for very smaller weights.
→ 1 gram (g) = 1000 milligram (mg).
→ Quintal and Tonne Used for very large weights.
→ 100 kg = 1 quintal and 1000 kg = 1 tonne
Capacity Measurements
→ Litre (L) Standard unit for larger volumes.
→ Millilitre (ml) Used for smaller volumes.
→ 1 L = 1000 ml
Key Conversions
→ To convert kilogram (kg) to gram (g), multiply by 1000 . e.g. 2 kg = 2 × 1000 g = 2000 g
→ To convert gram (g) to kilogram (kg), divide by 1000 . e.g. 5000 g = \(\frac{5000}{1000}\) kg = 5 kg
→ To convert gram (g) to miligram (mg) or L to ml, multiply by 1000 . e.g. 3 L = 3 × 1000 = 3000 ml and 3g = 3 × 1000 = 3000 mg.
→ To convert mg to g or ml to L , divide by 1000.
e.g. 4000 ml =\(\frac{4000}{1000}\) L = 4 L and 3000 mg = \(\frac{3000}{1000}\) g = 3 g
Operations
→ Addition and Subtraction
→ Convert to all to the same units first, then perform the addition or subtraction.
e.g. 2 kg 500 g + 1 kg 750 g = 2 × 1000 g + 500 g + 1 × 1000 g + 750 g [∵ 1 kg = 1000 g]
= 2000 g + 500 g + 1000 g+750 g = 4250 g
= 4000 g+ 250 g = 4 × 1000 g + 250 g
= 4 kg 250 g [∵ 1000 g = 1 kg]
Multiplication and Division
→ Method 1 Multiply or divide the quantities separately and then add the results of both multiplication or divison.
e.g.
4 × 10 kg 500 g = 4 × 10k + 4 × 500 g
= 40 kg + 2000 g
= 40 kg + 2 kg
= 42 kg
[∵ 1 g = \(\frac{1}{1000}\) kg]
→ Method 2 Convert the entire quantity in same unit then perform the multiplication or division.
e.g.
4 × 10 kg 500 g = 4 × (10 × 1000 g + 500 g) [∵ 1 kg = 1000 g]
= 4 × (10000 g + 500 g)
= 4 × (10500 g)
= 42000 g [∵ 1 g = \(\frac{1}{1000}\) kg]
= 42 kg [∵ 100]