Tuesday, September 8 th 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 $ You have been getting about $350/wk for about 12 weeks. You also got a $ 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 = $ $ 5700 OR $ ? 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, ,000,000 30,000,000 3,

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?

Zeroes between the decimal and the 4 are telling how SMALL the number is 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?

Ex: X 4.5 / Which of the three numbers has the FEWEST sig figs? has the fewest number of sig figs (2) ROUND your answer to 2 sig figs What your calculator tells you: Correct ans: 0.19

What is the correct answer? 45.6 X X / Your calculator gives you but you must round to Calculator gives you Can only have 2 sig figs Correct answer: 0.29

What is the correct answer? 6.7 x X X X / X

Ex: Which of the three numbers has the smallest amount of numbers past the decimal? EX: – What your calculator gives you:

What is the correct answer? Calculator gives you but you must round to 1 place past the decimal

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