Sungei Buloh

Hope you had fun at Sungei Buloh. For some of you, it may be your first time seeing huge monitor lizards, egrets and so on.

Just wanted to talk a little bit about conversion. There was a question about finding the volume of the pond. The surface area of the pond was 25 square metres and the depth was 6m.

Many of you obtained the volume by multiplying the surface area by the depth.
25 x 6 = 150
The volume is 150 cubic metres.
That is correct.

However, you were supposed to express your answers in litres. How?

The solution:
1 m = 100 cm
1 m x 1 m x 1 m = 100cm x 100cm x 100cm
1 cubic metre = 1000 000 cubic cm
150 cubic metres = 150 000 000 cubic cm

Since 1000 cubic cm = 1 litre,
150 000 000 cubic cm = 150 000 litres

Try to understand.
I will explain this again in class.

Have a good weekend.

Ratio

When asked to express a quantity as a fraction of another, look for the phrase "fraction of" and underline/highlight it. The quantity after "of" should be in the denominator.

E.g. 1
Joy is 12 years old and her mother is 35 years old. Express Joy's age as a fraction of her mother's age.
Her mother's age should be in the denominator.
So the answer is 12/35.

E.g. 2
Yvonne has 19 stamps. Tim has 31 stamps. What fraction of Yvonne's stamps is Tim's stamps?
Yvonne's stamps should be in the denominator.
So the answer is 31/19.

Solid Figures

We are almost at the close of the chapter.
Some things to take note of:
1) You need to use dotted lines to show the hidden edges of the solid figures.
2) The diagrams should be clear enough to show the shapes of the faces.
3) We learnt about 2 kinds of pyramids. One has 4 triangular faces only (It is also called a tetrahedron) and the other has 4 triangular faces and 1 square.
4) Do not say "The cuboid has 4 triangles and 2 squares." You should say "The cuboid has 4 triangular faces and 2 square faces".