6

What is mass?

Mass is a measurement of amount of matter something contains.

What is matter?

Matter refers to objects that take up space and have mass Mass is measured in units called Tonnes (t) Kilograms (kg) Grams (g) Milligram ( mg).

Units for measuring mass

• Identify the units

• Convert the following tonnes to kilograms

Example 1

 

5tonnes

Multiply tonnes by 1000 to

Change to kilograms

1t = 1000 kg

Therefore 5 t = 5 ×1000 kg

 

= 5000 kg

 

Example 2

Convert 0.327 tonnes to kilograms

0.327t

1t = 1000kg

Therefore 0.327t= ?

0.327 × 1000

=327 kg

 

Example 3

Kamau had 3.5 t,kiprono had 0.589t,while juma had ,2.4 t .How many kilograms do they have altogether

 

Solution

 

3.5t + 0.598 t + 2.4 t=?

  3.5

 0.598

+2.41

_____

6.508_____    

3.5t + 0.598 t + 2.4 t=?

  3.5

 0.598

+2.41

_____

6.508_____

3.5t + 0.598 t + 2.4 t=?

  3.5

 0.598

+2.41

_____

6.508_____

 

3.5t + 0.598 t + 2.4 t=?

  3.5

 0.598

+2.41

_____

6.508_____   1t = 1000kg

6.508 t = 6.508×1000kg

6508kg

Remember

• To change kilograms to tonnes .Divide kilograms by 1000

 Convert kilograms to tonnes

Remember

1000kg= 1t 

3000kg = ?

3000 

  = 3t (3 

 

72149 kilograms to tonnes

= 72149 divide by 1000

=72149    1000

=72.149 t

 More examples

What is the answer ?

9000 kg ------ ?

=9 tonnes

 

Work out 

QUESTIONS

Convert the following tonnes to kilograms

1. (a) 7 tonnes (b) 12.625 tonnes (c) 0.459 tonnes (d) 2 tonnes (e) 450 tonnes
2. Convert the following kilograms to tonnes (a) 4610kg (b) 922kg (c) Akello has 250kg ,Juma has 450 kg while Njeri has 300 kg of beans. How many tonnes do they have altogether? (d) 6 lorries carried 5000kg of sugar each . How many tonnes did they carry altogether? (e) 9250 kg

Answers