COUNT ON ME SINGAPORE Sum of the things that make us Singaporean


Who says Singaporeans don’t help the needy? Just look at our schools and companies. Growing up in Singapore brings a myriad of opportunities to take part in various Values in Action (VIA) activities in school, and Corporate Social Responsibility (CSR) initiatives when you join the workforce.

One common VIA/CSR activity is painting the walls of a children’s or old folks’ home. But how do we know how much paint to get to paint all the surfaces in the room (including the ceiling), if we measured the room’s dimensions to be 8.5m x 7m x 2.5m?

Assume that painting 1m2 will require 100ml of paint, and paint comes in 5-litre tins. Also assume that the room is in the shape of a cuboid, and all the surfaces are completely flat.


To find how much paint we need, we will need to find the total surface area of all the wall surfaces.

Surface Area

Area of a rectangle = Length x Breadth

So area of wall 1
= 8.5 x 2.5 = 21.25m2

Since the area of the wall opposite it is the same, the area of both walls
= 21.25 x 2 = 42.5m2

Area of wall 2
= 7 x 2.5 = 17.5m2

Area of wall 2 and the wall opposite it
= 17.5 x 2 = 35m2

Area of ceiling
= 8.5 x 7 = 59.5m2

Total area of all surfaces
= 42.5 + 35 + 59.5 = 137m2

Since 1m2 requires 100ml of paint, 137m2 would require
137 x 100 = 13,700ml of paint

Since 1 tin of paint contains 5,000ml of paint, we would need
13,7005,000 = 2.74 ≈ 3 tins of paint.

Use the formula to find out how much paint you would need to paint an old folks’ home, or even your own room!