tuesday, september 8 th grab your calculator prepare for warm up #4 test on thursday
Post on 17-Jan-2016
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Tuesday, September 8th
• Grab your calculator• Prepare for warm up #4• Test on Thursday
Warm up #4: I want a car!
• You are trying to save up for a car. The car costs $7500.00. You have been getting about $350/wk for about 12 weeks. You also got a $500.00 check from your grandparents for your birthday that you are going to use toward your car. You parents gave will give you $1000 towards the purchase of your car.
• How much money do you have so far?
350 X 12 = $4200 + 500.00 + 1000 $ 5700OR$ 5700.00?
DISCUSS
YOU ARE ONLY AS PRECISE AS YOUR LEAST PRECISE MEASUREMENT!
The bones
• These dinosaur bones are 85,000,004 years old
• Wow! That is VERY precise. How do you know exactly how old they are? I mean, down to the year?
• That’s easy! They were 85,000,000 years old when I started working here, and I have worked here for 4 years, so now they are 85,000,004 year old!
465,000• For large numbers, zeroes after the last non-zero number
before the decimal are giving information about the size of the number.
• The zeroes act as place holders that are still showing you the size of the number.
• 465,000 is NOT the same as 465, but both have the same number of significant figures
• If someone has a bank account and they say they have $465 in it, you think they are being very precise
• If someone has a bank account and they say they have $465,000 in it, you probably think that this is more of an estimate than an exact number
• More likely they would round that number up and say they have $500,000 or half a million
How many sig figs?
• 45,000• 450• 45• 300,000,000• 30,000,000• 3,000
• 2• 2• 2• 1• 1• 1
450.00
• How many sig figs?• 5• Think about it as if it were money: your mom
asks you how much money you have in your bank account to last until next payday.
• If you answer, “450 dollars,” your mom will think that you have ABOUT 450
• If you say, “ I have 450 dollars and zero cents,” it is more specific
How many sig figs?
• 56• 56.0• 56.00• 56.01• 56.10• 560.00• 5600.00• 5600• 560
• 2• 3• 4• 4• 4• 5• 6• 2• 2
0.000465
• Zeroes between the decimal and the 4 are telling how SMALL the number is
• 0.000465 is NOT the same number as 0.465, but they have the same number of sig figs
• The zeroes act as place holders
How many sig figs?
0.0050.05.050.03680.03600.0300.03000.00400560.00400500.0040000
1113333555
Ex: 35.00 X 4.5 / 823.465Which of the three numbers has the FEWEST sig figs?
4 2 6
4.5 has the fewest number of sig figs (2)ROUND your answer to 2 sig figsWhat your calculator tells you: 0.191264959
Correct ans: 0.19
What is the correct answer?
• 45.6 X 2.3
• 0.156 X 22• 6.7 / 23.461
• 105• Your calculator gives
you 104.88 but you must round to 105
• 3.4• Calculator gives you
0.285580324• Can only have 2 sig figs• Correct answer: 0.29
What is the correct answer?
• 6.7 x 9.45• 22.0 X 43.1• 3.14 X 65.90• 0.0560 X 22.45• 48.0 / 67.89• 0.0300 X 8.156
• 63• 948• 207• 1.26• 0.707• 0.245
Ex: 13.67 + 5.3785 - 2.9
Which of the three numbers has the smallest amount of numbers past the decimal?
EX: 13.67 + 5.3785 – 2.9
24
1What your calculator gives you: 16.1485
16.1
What is the correct answer?
• 14.678 +32.5
• 44.64 -50• 88.56 -42.673• 3.75 + 4.1• 21.342 -4.6• 31.2 + 4.56 -5.157
• 47.2• Calculator gives you
47.178 but you must round to 1 place past the decimal
• 5• 45.89• 7.6• 16.7• 30.6
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