Starter
Find the volume of the prism.
E
Alex pours melted
wax into moulds like
this to make candles.
4.3cm
5cm
4cm
F
200m
B
C
a) What volume of wax does he
need for each candle?
600m
A
800m
D
Alex melts this cube of wax.
b) How many candles can he
make with this wax?
18cm
Week 5A – Mindmap
Surface Area and Volume
Thurs 17 Feb
Nina, Shahin
DULWICH COLLEGE
|SINGAPORE|
Simplifying: Expanding
Brackets
KS3 Algebra
Week 5B – Dr Frost Maths
Volume and Surface Area
Mon 21 Feb
Nina, Teddy, Kasy, Emily,
Lewis, Lumi, Kara
Week 6A – Myimaths
Nets and Surface Area
Thurs 24 Feb
Expanding Brackets
Example:
4 (a + b)
Example:
e (e + 6)
Example:
3x – 2x(5 – x)
Expanding Brackets
Your Turn:
Simplify these expressions:
12 (3c + 9d) =
8p – 4 (p + 3) =
3p – 2c (7 – 4c) =
12c + 2p (3 – c) =
Questions
Simplify these expressions:
5 (x + 2y)
3(x + 2) + 4x
6 (x + 3)
2(m + 4) + 3(m + 6)
4 (y – 5)
4(t – 2) – 3(t + 1)
t (3t + 4)
11
4 (x – 3) + 2(5 – x)
-3 (m – n)
12
x (x + 4) + x (x – 3)
3x (x + y)
13
t (t + 1) – 4(t + 2)
-x (x + 2)
14
m(m – 4) + 2(m + 1)
Questions
Express the area of this rectangle.
DULWICH COLLEGE
|SINGAPORE|
Expansion of Brackets - Quadratics
KS3 Algebra
Expanding Two Brackets
• There are many approaches you can take to help you
multiply brackets
• So far we have seen:
• Now we will learn about:
– A term outside of the bracket
– Two brackets, side by side
4y(6 – y)
(y + 4)(y – 5)
24y – 4y
METHODS
Repeated bracket
Rainbows
Grid
Expanding Two Brackets
Repeated bracket
Rainbows
Grid
• Look at this algebraic expression: (3 + t )(4 – 2t )
Questions
(x + 5)(x + 4)
(x + 6)(x – 7)
(x + 6)(x + 5)
(x + 2)(x – 4)
(x + 1)(x – 3)
(3x + 1)(2x + 4)
(x + 5)(x – 1)
(3x + 2)(4x – 1)
(2x + 5)(x + 6)
(3x – 5)(x – 3)
Brackets with Squares
• When there are squares involved, the method is
the same – repeat the bracket twice and then
expand
(x – 4)2
Example: (x + 3)2
(2x + 5)2
(3x – 6)2