1. Key words: Square Triangle trapezium My Learning Outcome…
I will learn…
How to round to whole numbers , decimal places and significant figures.
I will apply my learning by…
Rounding .
I will evaluate my learning by…
Explaining to your partner how to round to 1 significant figure? L4
Rounding to nearest 10 or 100. L5
Rounding to decimal places. L6
Rounding to significant figures.
L7:
Be bale to understand standard form.
Learning Objective:
Application Tasks…

2. Rounding – to the nearest 10
Learn
L 4
Rounding – to the nearest 10
1 9 5
5 or more?
5 or more?
5 or more? No
Yes
Yes
2 0 0

3. Rounding – to the nearest 100
L 4
Rounding – to the nearest 100
Apply
8 9
5 or more?
5 or more?
5 or more? No
Yes
Yes
1 0 0
Copy &
complete
this table:
Number
To nearest 10
To nearest 100
To nearest 1000
37 521
9 875
452
37520
37500
38000
274500
274500
275000
Your Turn
9880
9900
10000
450
500

4. Rounding to 1 Decimal Place (1DP)
Learn
5 or more?
5 or more?
5 or more? No No
Yes
4 . 8
4 . 8
4 . 9
5 or more?
5 or more?
5 or more?
Yes
Yes
Yes
4 . 9
5 . 3
2 . 0

5. Rounding to Decimal Places: 2DP
Learn
5 or more?
5 or more?
5 or more? No
Yes
Yes
5 or more?
5 or more?
5 or more? No
Yes
Yes

6. Rounding to Decimal Places: 3DP
Learn
5 or more?
5 or more?
5 or more?
Yes No
Yes
5 or more?
5 or more?
5 or more? No
Yes
Yes

7. Rounding to Decimal Places
Apply
1DP
2DP
3DP
5 or more?
5 or more?
5 or more?
Yes No
Yes
4 . 9
Copy &
complete
this table:
Number
To 1DP
To 2DP
To 3DP
63.5
63.47
63.472
87.7
87.66
87.656
Your Turn
150.0
149.99 D
3.5
3.54
3.540
0.6
0.60
0.600

8. Significant Figures: Important Zeros in NumbersL6
Learn
Significant Figures: Important Zeros in Numbers 5 2 a.
Which zeros matter?
Are there any we could get rid of and still have the same value? 5 . 2 b. . 5 c. 2 . 5 d.
When dealing with Significant Figures, you need to keep any zeros that tell us the value of a number

9. Rounding to 1 Significant Figure (1SF)L6
Rounding to 1 Significant Figure (1SF)
Learn
5 or more?
5 or more?
5 or more?
Yes No No 1
2 4 1
5 8 7
7 5
5 or more?
5 or more?
5 or more? No
Yes
Yes
2 0 0
6 0 0
8 0

10. Rounding to 2 Significant Figure (2SF)L6
Rounding to 2 Significant Figure (2SF)
Learn
5 or more?
5 or more?
5 or more?
Yes No
Yes
1 . 4
5 or more?
5 or more?
5 or more?
Yes No
Yes

11. Rounding to 3 Significant Figure (3SF)L6
Rounding to 3 Significant Figure (3SF)
Learn
5 or more?
5 or more?
5 or more? No No No
5 or more?
5 or more?
5 or more?
Yes
Yes
Yes

12. Rounding to Significant Figures
Apply
1SF
2SF
3SF
5 or more?
5 or more?
5 or more?
Yes
Yes
Yes
Copy &
complete
this table:
Number
To 1SF
To 2SF
To 3SF
6.3528
34.026
6.35
6.4 6
34.0 34 30
Your Turn
0.0057
0.006 C
151
150
200

13. (Use the worksheet “powers of ten” for further explanation)
You need to understand about powers of 10.
Try these to test your previous knowledge.
Learn
105
10-1
102
103
101
10-2
106
10-3
Remember this?
100
104
(Use the worksheet “powers of ten” for further explanation)

14. 149 000 000 km 0.000 000 2 mm Standard Form is used a lot in maths and
Learn
Standard Form is used a lot in maths and
science as a convenient way of writing very
large, or very small numbers
for example:
The distance from the earth to the sun is km
huge!
A hydrogen atom has a diameter of about mm
microscopic!

15. Learn
Let’s deal with large numbers first.
Look at how these numbers have been broken down:
= 5 × 100
= 5 × 1 000
= 5 ×
= 5 × 102
= 5 × 103
= 5 × 104
you know how to write
these as powers of 10

16. Learn
What about these?
= 5.5 × 102
550
5 500
55 000
= 5.5 × 100
= 5.5 × 1 000
= 5.5 × 103
= 5.5 ×
= 5.5 × 104

17. Put these numbers into standard form:
Learn
Put these numbers into standard form:
4 000
= 4 × 103
= 4.5 × 102
= 5.5 × 104
= 3.5 × 103
= 7.5 × 105
6 000
= 6 × 103
= 4 × 102
= 8 × 104
= 9 × 103
= 4 × 105
450
400
55000
80 000
3500
9 000

18. × a number between 1 a power and 10 of ten but not including 10
Learn
Standard form is:
a number
between 1
and 10 ×
a power
of ten
but not including 10
positive or negative

19. Now try writing these numbers in standard form:
Apply
Now try writing these numbers in standard form:
= 5 × 106
= 5.5 × 106
= 5.25 × 106
= 5.1 × 106
= × 106

20. Reverse! Change each of these numbers
Learn
Reverse! Change each of these numbers
to an ordinary number
2.8 × 101
9.9 × 1010
7.1 × 104
3.97 × 102
8.172 × 102
6 × 102
2 × 103
5 × 107
9 × 108
3.7 × 109

21. The next stage is to write very
Learn
The next stage is to write very
small numbers, i.e. numbers less than 1
Check that you understand about
negative powers of 10
0.001 =
0.1 = = 10-1 10
0.01 = = =

22. Apply
Write in standard form:
0.007
0.04
0.0234
0.3

23. Change to small numbers
Apply
3.5 × 10-1
4.5 × 10-4
7.2 × 10-5
6.1 × 10-3
1.17 × 10-10

24. Change each of these to a large or small number:
Apply
1.115 × 104
1.412 × 10-3
7.2 × 101
9.01 × 10-2
1.17 × 106
5.5 × 10-6
6.5 × 10-8
3.2 × 105
2.9 × 102
3.167 × 10-11

25. How do you round to the nearest Significant figure?
Evaluate