1. Conversion of Metric Units

2. The Metric System
The International Metric System was developed and introduced in Europe in the times of Napoleon
It is based on the decimal numbering system
Conversion factors are always powers of 10 (i.e. larger units are 10, 100, 1000 of the base unit and smaller units are 1/10, 1/100, 1/1000 of the base unit)

3. The seven column table
This table and 3 simple rules will be the key to converting between units successfully
The middle column, with red borders, will hold the basic unit, metre (m), litre (l) or gram (g)
Larger units such as kilometre (km) or kilogram (kg) will go to the left and smaller subunits such as centimetre (cm), millimetre (mm), centilitre (cl), millilitre (ml) or milligram (mg) will go to the right

4. Metric Units - Distance
The base unit for measuring distance is the metre (m)
We use metres to measure:
The height of a door
The length of a corridor
The length and width of a room

5. Metric Units - Distancekm m
We use kilometres (km) for longer distances, such as:
The distance between cities (for example, between Madrid and Barcelona, or Auckland and Hastings)
The distance to the next services on the motorway
The distance from the Earth to the moon ( km)

6. Metric Units - Distancekm m mm
We use millimetres (mm) for very small things:
The thickness of a coin
The diameter of a screw

7. Metric Units - Distancekm m cm mm
We use centimetres (cm) for things like:
The width or depth of a washing machine
The height of a table
The width of a shelf

8. Metric Units - Distancekm m cm mm
There are other units in the empty columns, but we rarely see or use their names.
These missing units are, from left to right:
Hectometre (hm)
Decametre (Dm)
Decimetre (dm)

9. Check point 1
How many columns do you need for the Metric Unit Conversion Table?
In the Metric System …
What is the basic unit for distance?
What other metric units for distance do you remember?
Can you place them in the table?

10. Using the 7 column table
In the next few slides we are going to see how to use this table to convert between m, km, mm and cm.
We will start by writing the original measurement on the table
Then we will see ho to convert into the desired unit

11. Convert 32 cm into mm
STEP 1 - Write the original measurement into the table 3 2 cm km m cm mm 3 2

12. Convert 32 cm into mm
STEP 2 – Put the decimal point to the right of the target unit 3 2 cm = mm km m cm mm 3 2 .

13. Convert 32 cm into mm STEP 3 – Fill in with 0s as required 3 2 cm =
320 mm km m cm mm 3 2 .

14. Examples - STEP 1 Write on the table: 5 m 3 km 27 mm 512 cm 5 3 2 7 5

15. Place the decimal point:
Examples - STEP 2 km m cm mm
Place the decimal point:
5 m
3 km
27 mm
512 cm 5 3 7 2 1 . = km . = m . = cm . = m

16. Examples - STEP 3 Fill any gaps with 0s: 5 m 3 km 27 mm 512 cm 0.005
5 m
3 km
27 mm
512 cm 5 3 7 2 1 . =
0.005 km .
3 000 = m . =
2.7 cm . =
5.12 m

17. Check point 2 Draw the table and the column headings for distance
Use the table to convert the following numbers into cm: 350 m mm km mm

18. Metric Units - Weight g
The base unit for measuring weight is the gram (g)
A sugar cube weighs a few grams
We use grams to weigh sliced ham (200 g)

19. Metric Units - Weight kg g
A more familiar unit for weight is the kilogram (kg):
A bag of sugar weighs 1 kg
A normal wash-load is 1.5 kg
My weight is about 81 kg

20. Metric Units - Weight kg g mg
We use milligrams (mg) for very small things:
The amount of paracetamol in a tablet

21. Metric Units - Capacityl
The base unit for measuring distance is the litre (l)
A large bottle of Coke contains 2 l:
The petrol tank of an average car holds 40 l

22. Metric Units - Capacitykl l
Kilolitres (kl) are rarely used in everyday life
The capacity of a swimming pool could be measured in kl but is more commonly measured in thousands of litres instead

23. Metric Units - Capacitykl l ml
A teaspoon is about 5 ml
A can of coke is bout 330 ml

24. Metric Units - Capacitykl l cl ml
A bottle of wine is 75 cl
A drinking cup (paper) is about 20 cl

25. Metric Units - Summary km m cm mm kg g mg l cl ml

26. Conversion of Metric Units
Harder examples

27. Convert 3.2 kg into g
STEP 1 - Write the original measurement into the table 3 . 2 kg kg g mg 3 . 2

28. Convert 3.2 kg into g
STEP 2 – Put the decimal point to the right of the target unit 3 . 2 kg = g kg g mg 3 . 2

29. Convert 3.2 kg into g STEP 3 – Fill any gaps with 0s 3 . 2 kg = 3 200mg . 3 2

30. Check point 3 In the Metric System… What is the base unit for weight?
What other weight units can you remember?
What is the base unit for capacity?
What other units of capacity can you remember?

31. Harder examples - STEP 1 Write on the table: 0.5 m 3.5 kg 2.7 cl
kmkg
m g l
cm cl
mmmg ml
Write on the table: . 5
0.5 m 3 .
3.5 kg 5 2 . 7
2.7 cl
51.2 m 5 1 . 2

32. Move the decimal point:
Harder examples - STEP 2
kmkg
m g l
cm cl
mmmg ml
Move the decimal point: . 5
0.5 m = cm 3 .
3.5 kg mg 5 = 2 . 7
2.7 cl = ml
51.2 m km 5 1 . 2 =

33. Harder examples - STEP 3 Fill any gaps with 0s: 50 0.5 m = cm 3.5 kg
kmkg
m g l
cm cl
mmmg ml
Fill any gaps with 0s: 50 5 .
0.5 m = cm 3 .
3.5 kg mg 5 = 2 7 .
2.7 cl 27 = ml
0.0512
51.2 m km . 5 1 2 =

34. Check point 4 Use the conversion table to answer these questions:
How many cm in 1 m?
How many cl in 2 l?
How many g in 1kg?
1m is the same as _________ km
1mg is the same as __________ g