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Announcements
• Homework due NOW
• Make up exam after school till 3:15- better
come on time, because that is when ALL
exams will be collected.
• Break Packet tomorrow- will also be online.
Ways to represent answers
• Rounded- 3 decimal places unless told
otherwise
• Significant figures. The 0’s around the decimal
are NOT significant unless it is enclosed by
other numbers.
• Scientific notation/standard– 𝑎 𝑥 10𝑘 , 1 ≤ a <10
Rounding:
• Write 412.4563
– To the nearest tenth
– To 3 decimal places
– To the nearest integer
– To the nearest one hundreth
– To 3 significant figures
– To the one hundreds place
Rounding
• Write each to 3 significant figures
– 345.678
– .000345678
– 1200.002
– 34567.8
– 1010.1
– 19
Percent Error
𝑣𝐸 − 𝑣𝐴
𝑥 100
𝑣𝐸
• 𝑣𝐸 = 𝑒𝑥𝑎𝑐𝑡 𝑣𝑎𝑙𝑢𝑒
• 𝑣𝐴 = 𝑎𝑝𝑝𝑟𝑜𝑥𝑖𝑚𝑎𝑡𝑒 𝑣𝑎𝑙𝑢𝑒
Problems
• The area of a quilt is 2.35m2.
– Round this to the nearest whole m2.
– Round this area to the nearest tenth.
– Find your percent error between your two
solutions in the previous parts and the actual
area.
Problems
• The total length of 1000 identical hinges is
3064.2 cm. Calculate the length of one hinge,
in meters.
– Give your answer exactly
– Give your answer correct to three significant
figures
– Find the percent error between your answers to
part a and part b.
Problem
• Given the equation p = r2 + 2qr, calculate the
exact value of p when q=3.6 and r = 24
• Write your answer to 2 significant figures
• Calculate the percent error between the exact
answer from a and the approximate answer
from b.
Standard Form/ Scientific Notation
• Find the left most non-zero number
• Count the number of decimal places from just
the right of the digit to the current decimal
point.
• If we counted left, our k will be negative; if we
counted right, our k will be positive.
• Write down out number in standard form,
placing the decimal point where we counted
from before.
Practice
• Write the following numbers in standard form:
–
–
–
–
–
–
–
435000
.0087
.2
-.00456
.157
1900
-12005
Practice
• Write the following without using exponents
2. 006 X 107
-2 x 103
3.39 x 10-5
9 x 10-2
4.3 x 100
-7.5 x 101
-6.3 x 10-2
Advantage of Scientific Notation:
x 105)( 4 x 106)
3 x 4 x 105 x 106
12 x 1011
12
1.2 x 10
Multiplication: (3
Advantage of Scientific Notation
• Addition: (4.5 x 104) + (3.6 x 105)
4.5 x 104 + 36 x 104
40.5 x 104
4.05 x 105