Class 6 Maths — Letters for numbers
Write simple algebraic expressions and work out their value.
Name: ________________________
Before you start
The scale is level. Move the weights about and see what keeps it that way.
Take the same amount off both sides and it stays level. Take it off one side only and the scale says so at once — which is the whole rule for solving an equation, felt before it is written down.
1.Add weights from the shelf until both sides are equal.
Circle weights from the tray to make the scale level.
2.Take n = 5. Work out each expression, then sort it by its value.
Groups: Equals 10 · Equals 15
- 2n
- n + 5
- 3n
- n + 10
- n × 2
- 20 - n
3.Match each description to the expression that says the same thing.
- 7 less than m
- m shared equally between 7
- 7 times m
- 7 more than m
- 7m
- m + 7
- m ÷ 7
- m - 7
4.The scale is level and every box holds the same. What does one box weigh?
The scale is balanced. Write what one box weighs.
5.Two boxes, and x is what one of them weighs. Find x.
The scale is balanced. Write what one box weighs.
6.Which expression means 'three times a number n'?
- a) n + 3
- b) n - 3
- c) 3n
- d) n ÷ 3
7.If y = 9, what is the value of 2y - 4?
8.If n = 7, what is the value of 3n?
Answer key — Class 6 Maths — Letters for numbers
- 1. 5 on the right pan
- 2. 2n → Equals 10; 3n → Equals 15; n + 5 → Equals 10; n + 10 → Equals 15; 20 - n → Equals 15; n × 2 → Equals 10
- 3. 7 less than m → m - 7; m shared equally between 7 → m ÷ 7; 7 times m → 7m; 7 more than m → m + 7
- 4. box = 5
- 5. x = 4
- 6. c) 3n
- 7. 14
- 8. 21