 # Understand Metric Units of Mass

In this worksheet, students practise converting between metric units of mass. Key stage:  KS 4

GCSE Subjects:   Maths

GCSE Boards:   AQA, Eduqas, Pearson Edexcel, OCR

Curriculum topic:   Ratio, Proportion and Rates of Change, Mensuration

Curriculum subtopic:   Ratio, Proportion and Rates of Change, Units and Measurement

Difficulty level:   ### QUESTION 1 of 10

There are a number of units that can be used to describe mass, from pounds, ounces and tonnes to stones and grams. We are going to focus on the most common of these which is the metric measurement Grams.

All of the units you will have heard of that have the word gram in them are based around the base unit gram with other words tacked on to describe their relationships.

Kilogram - Kilo means 1000 so 1kg = 1000g

Centigram - Centi means 100 so 1cg = 100g (This one is very very rarely used)

Milligram - Milli means 1000 so 1g = 1000mg

How to convert.

Step 1: Decide on your conversion factor (i.e. g to kg is a conversion of 1000)

Step 2: Either multiply or divide by this number to get your converted numbers,

Example 1: Convert 150 g to kg.

Step 1: Decide on your conversion factor.

1000g = 1kg so our conversion factor is 1000

Step 2: Multiply or Divide,

You need to think about this a bit. The way I look at this is that a kilogram is bigger than a gram, so there will be less of them overall.

As there is less of them, we need to divide.

150 ÷ 1000 = 0.15 kg

Example 2: Convert 280g to milligrams.

Step 1: Decide on your conversion factor.

1000mg = 1g so our conversion factor is 1000

Step 2: Multiply or Divide,

You need to think about this a bit. The way I look at this is that a milligram is smaller than a gram, so there will be more of them overall.

As there is more of them, we need to multiply

280 x 1000 = 280000 mg

How many g are in 1 kg?

How many mg are in 1 g?

If I convert 370 g to kg. Is the answer...

0.37

370000

If I convert 1.21 kg to g. Is the answer...

1210 g

0.00121 g

Select if the following conversions are correct.

Select if the following conversions are correct.

Match the word with the correct conversion factor.

## Column B

milli
1000
centi
1000
Kilo
100

Change 375 g into kg.

Just put the number from you answer, don't worry about the units.

Change 4.3 kg into g.

Just put the number from you answer, don't worry about the units.

Change 204 g into mg.

Just put the number from you answer, don't worry about the units.

• Question 1

How many g are in 1 kg?

1000
EDDIE SAYS
The prefix kilo- means 1000 so there must be 1000g in a kilogram.
• Question 2

How many mg are in 1 g?

1000
EDDIE SAYS
The prefix milli- means 1000. There must bt 1000 mg in a gram.
• Question 3

If I convert 370 g to kg. Is the answer...

0.37
EDDIE SAYS
We know that g - kg is a conversion factor of 1000 (there are 1000g in 1 kg). The mistake that people make is to multiply here. Try to think that g are smaller than kg so there will be less of them.
• Question 4

If I convert 1.21 kg to g. Is the answer...

1210 g
EDDIE SAYS
We know that kg - g is a conversion factor of 1000 (there are 1000g in 1 kg). The mistake that people make is to divide here. Try to think that g are smaller than kg so there will be more of them.
• Question 5

Select if the following conversions are correct.

EDDIE SAYS
Did you remember to look at the conversions? mg to g = 1000 kg to g = 1000 Only one of the answers fits the pattern.
• Question 6

Select if the following conversions are correct.

EDDIE SAYS
Did you remember to look at the conversions? mg to g = 1000 kg to g = 1000 Did you spot the answer that didn't match this pattern?
• Question 7

Match the word with the correct conversion factor.

## Column B

milli
1000
centi
100
Kilo
1000
EDDIE SAYS
The one that catches people here is that even though we don't use centigram very often, we still have to know it. You just need to learn this little quirks.
• Question 8

Change 375 g into kg.

Just put the number from you answer, don't worry about the units.

0.375
EDDIE SAYS
Did you use the correct conversion factor? 1kg = 1000g. Remember that kg are larger than g so we need to have less of them. This means we need to divide.
• Question 9

Change 4.3 kg into g.

Just put the number from you answer, don't worry about the units.

4300
EDDIE SAYS
Did you use the correct conversion factor? 1kg = 1000g. Remember that g are smaller than kg so we need to have more of them. This means we need to multiply.
• Question 10

Change 204 g into mg.

Just put the number from you answer, don't worry about the units.

204000
EDDIE SAYS
Did you use the correct conversion factor? 1g = 1000mg. Remember that g are larger than mg so we need to have less of them. This means we need to divide.
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