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1. What are Unit Conversions?
Conversion between one unit of measurement of the same quantity to another is called a unit conversion. These conversions are done using simple operations of multiplication and division.
For example:
Capacity of water given millilitres can be converted into litres. Here millilitres is a smaller unit and litres is a larger unit.
Distance travelled in kilometres can be converted into metres or centimetres. Here kilometre is a larger unit while metres and centimetres are smaller units.
1.1 Metric Units
Units of length can be measured in kilometres, metres, centimetres and millimetres.
| 1 kilometre | 1000 metres |
| 1 metre | 100 centimetres |
| 1 centimetre | 10 millimetres |
Units of weight can be measured in kilograms, grams and milligrams.
| 1 tonne | 1000 kilograms |
| 1 kilogram | 1000 grams |
| 1 gram | 10 milligrams |
Units of volume can be measured in litres and millilitres.
| 1 litre | 1000 millilitres |
Let us now learn how to convert between different units of length, mass and volume.
1.2 Converting units with examples
To convert from a smaller unit to a larger unit, divide.
Example: A capacity of the bottle is 1200 millilitres. What is this capacity in litres?
Solution: Millilitre is a smaller unit and litre is a larger unit.
Divide to convert smaller unit to larger unit.
We know that 1 litre = 1000 millilitres
To convert 1200 millilitres to litres, divide by 1000
1200 ÷ 1000 = 1.2 litres
Capacity of the bottle is 1.2 litres.
To convert from a larger unit to a smaller unit, multiply.
Example: Joy cycles for a distance of 6.2 kilometres. What is this distance in metres?
Solution: Kilometre is a larger unit and metre is a smaller unit.
Multiply to convert larger unit to smaller unit.
We know that 1 kilometre = 1000 metre
To convert 6.2 kilometres to metres, multiply by 1000
6.2 × 1000 = 6200 metres
Joy cycles 6200 metres.
2. Units of Time
Measuring time is measuring the length or duration of the time. Time is measured in seconds, minutes, hours, days, weeks, months and years.
Let us now see the relationship between different units of time.
| 1 minute | 60 seconds |
| 1 hour | 60 minutes |
| 1 day | 24 hours |
| 1 month | 7 days |
| 1 year | 365 days
(366 days in a leap year) |
2.1 Time Conversion: Solved Example
Convert 5 days 4 hours into hours.
Solution:
For converting 5 days 4 hours to hours, the first step is to convert 5 days to hours.
Hour is a smaller unit and day is a larger unit.
Multiply to convert smaller unit to larger unit.
We know that 1 day = 24 hours
To convert 5 days to hours, multiply by 24
5 × 24 = 120 hours
Now, 5 days 4 hours = 120 hours + 4 hours = 124 hours
