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

You can read the posting on **Sarin’s family and Ramadan** in Welcome page about story of Sarin’s family during Ramadan.

Read the posting on **Sarin learns Symbol, Algebra and Equation in school (Math Concept)** to understand the concept of Algebra Expression.

To read also the postings on **Sarin learns the concept of Fraction (mathematics concept)** to understand the concept of Fraction.

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

**Upper primary school mathematics question UPQ518**

During Ramadan, Sarin’s mother baked two types of cakes as the family contribution to the mosque for consume after breaking fast. She baked 24 more chocolate cakes than strawberry cakes. 2/3 of the chocolate cakes and ¾ of the strawberry cakes were consumed during dinner when breaking fast. At the end of the dinner, there were 71 cakes left.

(a) How many chocolate cakes did Sarin’s mother bake altogether?

(b) How many strawberry cakes did Sarin’s mother sell?

Solution:

Using Algebra Expression or equation,

Since 2/3 fraction of the chocolate cakes consumed.

We set the total chocolate cakes as 3C. Consumed 2C and left with 1C

Similarly for strawberry cakes,

Set the total strawberry cakes as 4S. Consumed 3S and left with 1S

Sarin’s mother baked 24 more chocolate cakes than strawberry cakes,

The equation or algebraexpression,

3C = 4S + 24

Based on the left over cakes,

We have 2^{nd} equation or algebra expression,

1C + 1S = 71 ==> 3C = 213 – 3S

Hence,

4S + 24 = 213 – 3S

7S = 213 – 24 = 189

1S = 27

1C = 71 – 27 = 44

The number of chocolate cakes baked = 3C = 3 × 44 = 132

The number of strawberry cakes sold = 3S = 3 × 27 = 81

Alternative Solution:

Using math model,

Chocolate cakes was 24 more than strawberry cakes

Since, the number of left over cakes are 71

From the model,

7 units + 8 = 71

7 units = 63

1 unit = 9

The number of chocolate cakes baked = 12 × 9 + 24 = 132

The number of strawberry cakes sold = 9 × 9 = 81