# P6 Algebra questions

Looking for some Primary 6 Algebra questions for your Math revision?

### Question 1: Simplify the algebraic expression below

*(Adapted from 2018 SNG Primary 6 CA1 Math Paper 1 Question 3)*

9 + 5g – 2 + 4g = ?

**Answer:**

9 + 5g – 2 + 4g (Step 1: Group the numbers together, then the terms)

= 9 – 2 + 5g + 4g (Step 2: Simplify the equation)

= 7 + 9g

### Question 2: Write an algebraic expression

*(Adapted from 2018 Maha Bodhi Primary 6 CA1 Math Paper 1 Question 6)*

Don is 11 years old. He is f years older than Donki.

How old is Donki?

**Answer:**

Since Don is older, Donki must be the younger one.

Age of Donki = (11 – f) years old

### Question 3: Solve an algebraic equation by substitution

*(Adapted from 2018 ACS Primary 6 CA1 Math Paper 1 Question 8)*

Find the value of 4y – (y + 3)/2 + 10 when y = 5.

**Answer:**

4y – (y + 3)/2 + 10 (Step 1: Replace y with 5)

= (4 x 5) – (5 + 3)/2 + 10 (Step 2: Use order of operation. Solve the brackets first)

= 20 – 8/2 + 10 (Step 3: Solve the division part next)

= 20 – 4 + 10 (Step 4: Solve the subtraction part)

= 16 + 10 (Step 5: Solve the addition part)

= 26

### Word problem sum 1: Write simple algebraic equation and simplify them

*(Adapted from 2018 Nanyang Primary 6 CA1 Math Paper Question 29)*

The mass of a bag of rice is n kg.

The mass of a baby is twice as heavy as the bad of rice.

The mass of a school bag is 5 kg more than the mass of the baby.

What is the mass of the school bag? Give your answer in terms of n.

**Answer:**

Mass of the baby = 2n

Mass of the school bag = (2n + 5) kg

### Word problem sum 2: Higher level algebra challenge

*(Adapted from 2018 Nanyang Primary 6 CA1 Math Paper Question 14)*

Alvin had $10y. He had $24 less than Claire. Linda had half as much as Alvin. They bought a birthday cake for their mum which cost $(4y+5).

a. How much did they have altogether at first?

Give your answer in terms of y in the simplest form.b. If y = 7, how much did they have left in total after buying the birthday cake?

**Answer to part a:**

Amount of money that Claire has = $(10y + 24)

Amount of money that Linda has = $(10y/2) = $5y

Amount of money that they had at first = $10y + $10y + $24 + $5y = $(25y + 24)

**Answer to part b:**

Amount of money that they had at first = $25y + 24 = ($25 x 7) + $24 = $175 + $24 = $199

Cost of the birthday cake = $(4y + 5) = ($4 x 7) + $5 = $28 + $5 = $33

Amount of money they have left after buying the birthday cake = $199 – $33 = $166

### Bonus Primary 6 Algebra Practice Question:

*(Adapted from PSLE Math paper 2018)*

XYZ Police Post received reports of 16 scams, 2n scams and 2 + n scams monthly for the period of October to December respectively.

“The number of scam cases happened in October.”

Is the sentence above True, False or Impossible to Tell?

**Answer:**

### Need more help on Primary 6 Algebra?

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If you need to brush up on some areas of Algebra, do check out this simple guide where we explain the basics about everything you need to know for Primary 6 Algebra!