Maths Week 2 Lesson 1 work
Warm up:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
1+4=5
38+62=100
1
128-10=118
120+90=210
124=90+34
610-606=4
1×7=7, so 7÷1=7
11:07
18 minutes
Area
Area is a measure of surface and is often referred to as the amount of space contained inside a twodimensional space.
The common metric units for are include:
Square millimetres (mm²)
Square centimetres (cm²)
Square metres (m²)
Square kilometres (km²)
Hectares (ha)
1. Convert 0.248 m² to cm²
0.248𝑚² = 0.248 × 10000
= 2480 𝑐𝑚²
2. Convert 1 mm² to cm²?
1 𝑚𝑚² = 1 ÷ 100
= 0.01 𝑐𝑚²
Finding areas of shapes
Square-Area=length x length
E.g. A= l2
= 3 x 3= 9cm2
Rectangle- Area= length x width or A=lw
E.g. A=lw
= 7 x 3= 21m2
Triangle- Area=1/2 base x height or A=1/2bh
E.g. A= 1/2bh
= ½ of (10 x 7)
=70÷2= A=350mm2
A triangle has area 20 cm2 and base 4 cm. Calculate its height.
A = ½ (b x h)
20= ½ (4 x h)
20= 2 x h
20 ÷ 2 = h
10 = h
The height is 10 cm
Skill development practice
4a. 2cm2 = 200mm2
4d. 3ha=30000m2
4g. 3090mm2=309cm2
4j. 450000m2= 450km2
4m. 320000m2= 32ha
4p. 4802cm2= 48.02 m2
4s. 0.0049ha= 49m2
5a. A=l2= 3 x 3=9cm
5b. A= l x w= 7 x 3 = 28m
5c= A=1/2bh= ½(13 x 6)=1/2 of 78=39 cm
7a. 22mm2
7b. 0.0473cm2
7c. 340km2