The blog postings are about the Singapore Math. The readers can learn from the postings about Solving Singapore Primary School Mathematics. The blog presenting the Math Concept, Math Questions with solutions that teaches in Singapore Primary Schools. You or the kids can learn the skills of dealing with Math Modeling, Problem Sum from Lower Primary School to Upper Primary School level. This posting is an upper primary school math question on Problem Sum.

Read the posting on** Sarin’s family in Kluang **about Sarin’s family venture in Kluang.

*Challenge yourself with the question before look out for the solution‼!*

**Upper primary school mathematics question UPQ252**

Fatimah’s mother gave some money to Fatimah for her to spend in the Popular Book Co. at Kluang town. After spending $31 on 5 note books and 8 files, she was short of of $0.40 if she were to buy another note book. However, she would have $0.60 left if she were to buy one more file.

a) How much did a notebook cost?

b) How much money did Fatimah’s mother give to her?

Solution:

Draw the cost model

Per the model

5 units + 5 + 8 units = 31

13 units = 26

1 unit = 2

The cost of a note book = 1 unit + 1 = 2 + 1 = $3.00

The amount of money Fatimah mother gave = 31 + 3 – 0.4 = $33.60

Alternative solution:

By equations

Draw the unit cost model

Set : Cost of 1 note book = N

Cost of 1 file = F

From the unit cost model

Cost of 1 note book (N) = Cost of 1 file (F) + 0.6 + 0.4

Equation 1: N = F + 1

And,

Equation 2: 5N + 8F = 31

Solve: 5(F + 1) + 8F = 31

13F = 26

F = 2

N = 2 + 1 = 3

The Cost of a note book = $3.00

The amount of money Fatimah mother gave = 31 + 3 – 0.40 = $33.60