50
55
60
TIMELY TIPS 3
5
45
40
50
15
35
55
30
60
25
5
45
40
50
20
35
55
30
60
25
5
30
25
The clock face is divided into 12 equal sections, each representing 5 minutes.
We can use the clock face to look at fractions and decimals a bit more.
We know there are 60 minutes in an hour so 5 minutes can be written as a
fraction like this: 5/60 (we can think of it as 5 out of 60).
10
20
This shows that, as fractions of an hour, 5/60 is the same as 1/12
10
15
35
In this clock face the minutes have been marked in, not the hours.
Looking at the clock face again we can see that this 5 minutes is the same
as one complete section, so we can write it as a fraction like this: 1/12 (1 out
of 12)
15
45
40
10
20
We call them equivalent fractions.
What about this clock face? How many equivalent fractions can we use to
describe the blue part of the face?
•
Perhaps we think of a quarter of an hour first, so 1/4
•
But we know it’s also 15 minutes, so we get
•
And we can also see it’s 3 sections of the clock face which is 3/12
•
So we can say that 1/4
15
15
/60
/60 and 3/12 are equivalent fractions.
Fractions are a short way of showing a division sum. 1/4 means……
1 divided by 4
Get your calculator and do the division sums for 1/4
15
/60 and 3/12
(Remember it’s the top number divided by the bottom number so put the
top number in first. Your answer is going to be less than one.)
Did you get the same answer each time? Well done – you’ve just
learned how to change a fraction to a decimal.
Have a go at finding the equivalent fractions for the shaded part of these three clock
faces.
If each member of boyband
One
Direction
tweets
10 times in one hour, how
mant tweets do One
TryDirection
these
make in a week
Now change those fractions to decimals.
35
30
25
45
40
20
15
35
30
25
20
50
60
5
45
40
10
15
35
30
25
20
1
15
10
55
1.
40
50
5
3
45
10
60
55
2.
5
20
60
3.
50
55
/60, 4/12 , 1/3 All of these are 0.33 as a decimal
/4, 45/60. 9/12 All of these are 0.75 as a decimal
/60, 6/12 All of these are 0.5 as a decimal
10 mins =
5 mins =
2
1
/12 or 10/60 = 0.166
/12 or 5/60 = 0.083
3. I’ve worked 8hrs 25 minutes today.
What’s my pay at £9.32 per hour?
30
2. What is 10 minutes?
/2,
1. Use your calculator to find out what 5 minutes is as a decimal of an hour.
£78.45 (to nearest penny)
8.417 x £9.32 = £78.446
hourly rate:
Multiply total time worked by
Total time worked is 8.417 hours
25 ÷ 60 = 0.417
Change the 25 mins to a decimal: