1. Converting between different units
Mathematics
Converting between different units

2. Lesson Objectives The aim of this powerpoint is to help you…
Convert between different types of metric units for
Length
Mass
Capacity

3. Metric Units LENGTH millimetre (mm) [centimetre (cm) 1cm = 10mm]
metre (m) 1m = 1000mm
kilometre (km) 1km = 1000m

4. Metric Units MASS (WEIGHT) milligram (mg) gram (g) 1g = 1000mg
kilogram (kg) 1kg = 1000g
tonne (T) 1T = 1000kg

5. Metric Units CAPACITY millilitre (ml) [centilitre (cl) 1cl = 10ml]
litre (l) 1l = 1000ml

6. Metric Unit Conversions
For length, capacity and mass if ‘centi’ is not involved, you need 1000 units to make 1 of the next sized units
To convert large type units to smaller ones, multiply by lots of 1000
To convert smaller type units to larger ones, divide by lots of 1000

7. Multiplying/Dividing by 1000
1000 is 1 followed by 3 zeros
Multiplying by 1000 results in moving the decimal point 3 places to the right to make the number bigger
Dividing by 1000 results in moving the decimal point 3 places to the left to make the number smaller

8. LOGIC Check your answers by asking yourself whether they make sense.
If they do NOT make sense you have probably multiplied when you should have divided or vice versa!
Remember if you have big units and you change them to smaller ones there will be a lot more of the smaller ones!

9. Example 1 Convert 7m to millimetres Metres are bigger than millimetres
Converting bigger to smaller  multiply by…
‘Centi’ is not involved so  1000
7m × 1000 = 7000mm

10. Example 2 Convert 85ml to centilitres
Millilitres are smaller than centilitres
Converting smaller to bigger  divide by…
‘Centi’ is involved and the link between ‘centi’ and ‘milli’ is  10
85ml ÷ 10 = 8.5cl

11. Example 3 Convert 0.64km to millimetres
Kilometres are bigger than millimetres
Converting bigger to smaller  multiply by…
‘centi’ is not involved so  1000 (twice!!!)
0.64km × 1000 = 640m × 1000 = mm

12. What next?
Print out the notes called Meas2. Read through them and make sure you answer any questions on page 6.
Work through the MyMaths lesson and its online homework called Metric Conversion found at:
Now move on to the Meas2b powerpoint