Transcript Volume of Prisms

Significant Numbers
www.mathsrevision.com
Int 2
Significant Numbers
Using Standard form
Starter
www.mathsrevision.com
Int 2
Q1.
Round the following to 2 decimals places.
(a) 3.5647
(b) 4.55732
(c) 3.98111
Q2. Write in standard form.
(a) 12300 (b) 0.0034 (c) 0.0005
Q3.
Write out in full.
(a) 2.8 x 10 3
(b) 1.19 x 10-2
(c) 4.5 x 10-1
Significant Numbers
www.mathsrevision.com
Int 2
Learning Intention
1. To understand the
term significant numbers
for decimals and whole
numbers.
Success Criteria
1. To know the meaning of
significant number.
2. Apply knowledge to
problems.
Significant Numbers
www.mathsrevision.com
Int 2
In mathematics a figure or digit is significant
if it gives an idea of both:
(i) Quantity
(ii) Accuracy
It is similar to rounding and all to do with zero’s
Significant Numbers
www.mathsrevision.com
Int 2
Decimal numbers
0.04
1 significant figures
0.37
2 significant figures
1.04
3 significant figures
0.306
3 significant figures
1.30
3 significant figures
0.90
2 significant figures
What is
the first
0’s at the beginning DON’T count
rule?
What is
the second
rule?0’s in the middle DO count
What is
the third
0’s a the end DO count
rule?
Significant Numbers
Int 2
www.mathsrevision.com
Easy rule :
Just remember 0’s at the beginning DON’T count
Exercise : Round to 2 sig figures
1.24
1.2
55.24
55
2.307
2.3
12.307
12
0.445
0.45
0.08445
0.084
0.0162
0.016
0.00106
0.0011
0.003398
0.0034
0.030467
0.030
0.0103290
0.010
0.0503990
0.050
Significant Numbers
www.mathsrevision.com
Int 2
Whole Numbers
106
3 significant figures
9087
4 significant figures
360
? 2 / 3 significant figures
0’s in the middle DO count
What is
the rule
0’s at the end MAY or MAY NOT
count depending on the question.
There are 360 degrees in a circle.
3 significant figures
358 to the nearest ten is 360.
2 significant figures
Significant Numbers
Int 2
www.mathsrevision.com
Easy rule :
0’s at the end MAY or MAY NOT count
Exercise : Round to 2 sig figures
15030
15000
55
55
230
230
1094
1100
17693
18000
445
450
135
140
50298
50000
1378409
1400000
10000
10000
1155
1200
314
310
Significant Numbers
www.mathsrevision.com
Int 2
Now try MIA Ex 1
Ch16 (page 3)
Starter
www.mathsrevision.com
Int 2
Q1.
Round the following to 2 decimals places.
(a) 26.555
(b) 434.815732
(c) 563.0844
Q2. Write in standard form.
(a) 58300 (b) 0.6734 (c) 0.09475
Q3.
Write out in full.
(a) 2.3 x 10 5
(b) 8.99 x 10-3
(c) 6.5 x 10-2
Significant Numbers
www.mathsrevision.com
Int 2
Learning Intention
1. Work with a calculator to
solve problems to specific
significant figures. Also
convert between normal
form and scientific
notation.
Success Criteria
1. Convert between and normal
form and scientific notation.
2. Use calculator to work
problems to a specific
significant figures.
Significant Numbers
Int 2
www.mathsrevision.com
Standard Form / Scientific Notation
a × 10
n
Normal mode
1 ≤ a < 10
n = Integer Number
2.001 ×103
4 Sig. fig.
2001
5.6×10-2
2 Sig. fig.
0.056
5.647 ×102
4 Sig. fig.
564.7
Standard form
always indicates the number of significant figures
Significant Numbers
www.mathsrevision.com
Int 2
Now try MIA Ex 2
Ch1 (page 5)