Sig. Fig PPT

Significant Figures
Rounding to Decimal Places
10 multiple choice
questions
Round to
1 dp
0.34
A)
0.4
B)
0.3
C)
0.35
D)
3
Round to
1 dp
0.48
A)
0.49
B)
0.4
C)
0.47
D)
0.5
Round to
1 dp
2.75
A)
2.8
B)
2.74
C)
2.7
D)
3.0
Round to
1 dp
13.374
A)
13.0
B)
14.0
C)
13.3
D)
13.4
Round to
1 dp
26.519
A)
25.0
B)
26.6
C)
26.0
D)
26.5
Round to
2 dp
23.1782
A)
23.20
B)
23.18
C)
23.10
D)
23.17
Round to
2 dp
500.8251
A)
500.80
B)
500.8
C)
500.83
D)
500.84
Round to
3 dp
0.00417
A)
0.00417
B)
0.004
C)
0.00418
D)
0.005
Round to
2 dp
4.999
A)
4.99
B)
4.90
C)
5.00
D)
4.98
Round to
4 dp
0.72995
A)
0.7300
B)
0.7390
C)
0.7210
D)
0.7399
Decimal Places
• When we round to decimals, we start
counting as soon as we reach the decimal
point.
Round 17.46789 to 2 decimal places
1 decimal place
2 decimal places, this will
stay a 6 or go to a 7
depending on what the
next number is
Significant Figures
• When we round to significant figures, we start
counting as soon as we reach a number that is
not zero
Round 17.46789 to 2 significant figures
1 significant figure
2 significant figures, this
will stay a 7 or go to
a 8 depending on
what the next
number is
All the numbers after
will become zero
Round 17.46789 to 2 significant figures= 17.00000 or
just 17
Round to
1 sf
43 07 08 50 03 07
Look at the next number
It’s more than 4 so we round up!
Round to
3 sf
3 7 8 04 03 07
Look at the next number
It’s less than 5 so we round down!
Round to
2 sf
0 . 0 0 2 98 9
Look at the next number
It’s more than 4 so we round up!
Round to
3 sf
0 . 0 0 2 0 98 7
Look at the next number
It’s more than 4 so we round up!
Rounding to Significant Figures
Main
1. When you are rounding to decimal
places you start counting after the
decimal point, but with significant
figures you start counting at the
first non zero number
2.
i. 1000 1500 1460
ii. 200 160 157
iii. 40 37 37.1
iv. 6 6.1 6.09
v. 0.006 0.0064 0.00640
3.
a) 4.7
b) 0.058
c) 0.19
d) 540
Rounding to Significant
Figures (sig fig or s.f)
10 multiple choice
questions
Round-
0.23 to 1 s.f
A)
0.3
B)
2
C)
0.2
D)
3
Round-
0.045 to 1 s.f
A)
0.04
B)
0.1
C)
0.0
D)
0.05
Round-
623 to 1 s.f
A)
600
B)
620
C)
630
D)
700
Round-
5328 to 1 s.f
A)
5300
B)
5000
C)
5330
D)
6000
Round-
0.005136 to 2 s.f
A)
0.01
B)
0.0050
C)
0.00514
D)
0.0051
Round-
426.213 to 2 s.f
A)
426.21
B)
430
C)
400.00
D)
420
Round-
3002.01 to 3 s.f
A)
300
B)
3000
C)
3010
D)
3002.0
Round-
983.4 to 1 s.f
A)
100
B)
900
C)
980
D)
1000
Round-
0.00456 to 2 s.f
A)
0.0045
B)
0.004
C)
0.0046
D)
0.00
Round-
36345.3 to 3 s.f
A)
36300
B)
4000
C)
36000
D)
45300