Significant Figure Rules
Significant or Not Significant?
Digits 1-9
Significant
Round 676767 to the nearest thousand.
677000
Express the following as decimal numbers
8.71 x 10^6
8,710,000
When x = 2,
10 + 3(12 ÷ (3x)) = ?
16
The number of pupils, n, in a school was approximated to 1400 to the nearest 100.
1350≤n<1450
Significant or Not Significant?
Zeroes before non-zeroes
Not Significant
Round 8922 to 1 s.f.
9000
Express the following in Scientific notation
1392.0009
1.3920009 x 10^3
What value of x satisfies the equation −3(4x − 5) = 2(1 − 5x) ?
13/2
A door was measured as 92cm wide to the nearest centimetre.
Upper bound =92.5cm
Lower bound =91.5cm
How many significant figures are in the number:
390.00
5
Round 2.4762 to 3 s.f.
2.48
Express the following as ordinary numbers
8.32158 x 10^-4
0.000832158
What is 3% of 4.14 × 10^4 ? Give your answer correct to the nearest integer.
1,242
The population of a town, y, is given as 280000 people rounded to the nearest 10000. Find the upper and lower bounds of y.
275000≤y<285000
Correct answer varies.
Example: 60.608
Round 0.005109 to 3 s.f.
0.00511
Express the following in Scientific notation
0.010097
1.0097 x 10^-2
About 1.48 × 10^8 square kilometers of Earth’s surface is land; the rest, about 3.63 × 10^8 square kilometers, is water. If a returning space capsule lands at a random point on Earth’s surface, what is the best estimate of the probability that the space capsule will land in water? Give your answer correct to the nearest 3 sig figs.
71%
A number was given as 38.6 to 3 significant figures. Find the upper and lower bounds of the number.
38.55≤y<38.65
Create and label a number that contains all of the following:
Leading Zeros
Trailing Zeros
Non-Zeros
Sandwich Zeros
Answer Varies
Example: 0.0040900
Write down how to round 516,908 correct to 3 significant figures.
Reading from left to right, look to the digit to the right of the third digit. This digit (the 9) tells me to round up, therefore my answer is 517,000.
Define Standard Form.
Scientific or Standard Notation is best used to express very large or very small numbers in a compact, easy to read form, but can be used on any numbers.
Solve the System of Equations
−x − y − 3z = −9
z = −3x − 1
x = 5y − z + 23
(−2, −4, 5)
A rectangle has a width w of 3 cm to the nearest centimetre and a length l of 8.6 cm to the nearest millimetre. Find the upper and lower bounds of the perimeter, P, of the rectangle.
Lower bound of P = 2(2.5+8.55) = 22.1 cm
Upper bound of P = 2(3.5+8.65) = 24.3 cm