4. What does the digit 5 in 22.835 represent? Try fi lling in the number on a notation board.
TU 1 __
10
___ 100
1
____ 1000
1
5. Draw notation boards to represent the following numbers. a) 124.955 d) 745.4
b) 613.419 e) 29.632
c) 60.178 f) 8.005
When measuring, we use the prefi xes kilo and milli. Kilo means a thousand times bigger and milli means a thousand times smaller. If you look at your ruler, the smallest measurement is a millimetre, or mm.
Each mm = 1 So 2mm = 2 3mm = 3
____ 1000 of a metre, or 0.001m.
____ 1000m = 0.00 m.
____ 1000m = 0.00 m
0123456789 10 cm
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
6. Now write these lengths as decimals of a metre. a) 4mm
b) 7mm c) 6mm
d) 9mm
e) 5mm
Kilo is used in the words kilogram (a thousand grams), kilometre (a thousand metres). If we are measuring items smaller than a kg or km, we can use the decimal system. 1g = 1
____ 1000kg = 0.001kg
2m = 2
____ 1000km = 0.002km
7. Write these measurements as kg or km using the decimal system. a) 7g = 0.00 kg d) 65g g) 237g