Question

What is the best order-of-magnitude estimate for 0.0008?



A.


10^-3


B.


10^-4


C.


10^-5


D.


10^-6

Answer 1

first put the number into scientific notation

Answer 2

the order of magnitude is the power of 10

Answer 3

so is it A?

Answer 4

.0008 = 8 x 10^-4

Answer 5

so B ?

Answer 6

correct

Answer 7

explain?

Answer 8

the order of magnitude is the power of 10 , it ignores the digit 8

Answer 9

it just wants to know your 'decimal'

Answer 10

thats the order of magnitude

Answer 11

ok here is an example

20 meters. whats the order of magnitude

2 is in the tens place, so 10 is the order of magnitude.
we can write this as 2.0 x 10^2

Answer 12

ohhhhh okay

Answer 13

:)

Answer 14

thank you lots

Answer 15

oh, we should be careful about terminology

Answer 16

theres a difference between 'order of magnitude estimate' and 'order of magnitude'

Answer 17

one moment

Answer 18

ok, order of magnitude estimate, which power of ten is your number closest to?

Answer 19

.0008 , is it closer to .0010 or .0001

Answer 20

it was A

Answer 21

right, it is closer to .001

Answer 22

because .0008 is closer to .001 than to .0001

Answer 23

.0008 + .0002 = .0010

.0008 - .0007 = .0001 ,

so it is closer to .001

Answer 24

also it helps to think of it like this.
round your answer to the nearest power of 10
powers of 10 are 100,10,1,0.1,0.01,0.001, etc

Answer 25

what power of 10 is .0008 closest to?

Answer 26

http://en.wikipedia.org/wiki/Order_of_magnitude

Answer 27

99 is written in scinote as 9.9x10^1. So is it's order of magnitude 10^1? Just 10 ? 100, 10^2, is much closer.

Answer 28

99 is written in scinote as 9.9x10^1.

So is it's order of magnitude 10^1?

but 99 is much closer to 100, or 10^2.

therefore 99 has order of magnitude 10^2 (order of magnitude estimate