Question

A brand new one-dollar bill is 4.3 x 10 -3 inches thick. What would be the thickness, in inches, of a stack of a 200 brand new dollar bills?
A) 0.63
B) 0.86
C) 6.3
D) 8.6

Answer 1

the problem is essentially just multiplying the 2 numbers together,
whether you want to convert \[4.3 * 10^{-3}\] to regular notation first
or convert 200 to scientific notation before multiplying is up to you

Answer 2

ok, that makes sense

Answer 3

im confused again

Answer 4

What does \[4.3*10^3\] equal to?

Answer 5

I mean \[4.3*10^-3\]

Answer 6

for the exponent it is supposed to be -3 ...
That is one thing that i am having troubles with

Answer 7

i can do the positive, but i have a hard time doing the negative

Answer 8

When you do the negative, you are basically taking the decimal backwards instead of forwards.

Answer 9

ohhh

Answer 10

Still need help?

Answer 11

\[10^0 = 1\]
\[10^{-1}=0.1\]
\[10^{-2}=0.01\]
etc

if that helps

Answer 12

So since it is negative, the answer would be either A or B?

Answer 13

Not always. Just continue with what we are doing right now. What is 4.3 * 10^-3

Answer 14

Well let me ask you this, what is 4.3 *10^3 without the negative?

Answer 15

umm...i know 4x3 is 12...and i do believe 10^3 is 30

Answer 16

so would i have to multiply those 2 numbers?

Answer 17

10^3 is not thirty! 10^3 means 10*10*10

Answer 18

oh.. well im sorry.. im struggling with pre algebra

Answer 19

It's okay. Here is a tip, where you are doing 4.2 * 10^3, you just move the decimal to the right three times and add zeros.

Answer 20

wait, its 1000

Answer 21

my bad

Answer 22

You are correct, now just multiply the two numbers like you said before.

Answer 23

do i do any dividing at all?

Answer 24

Nope, just multiply.

Answer 25

i think i just did my math really wrong

Answer 26

What did you get? It's okay if you did it wrong.

Answer 27

i multiplied 1000 by 12 and got 12000

Answer 28

Why are you multiplying by 12? Isn't it 4.2?

Answer 29

I mean 4.3

Answer 30

so your saying i have to multiply 4.3 by 1000 ?

Answer 31

Yep.

Answer 32

ok give me a second

Answer 33

now i got 4300

Answer 34

Correct! However, 4300 is what you get when you do 4.3 * 10^3. We need to do 4.3 * 10^-3. To do that, you just take the two zeros from 4300 and put it to the front and add a decimal in the front.

Answer 35

so it would be something like..
00.43 ?

Answer 36

or
.0043

Answer 37

Yep, .0043.
Just for practice, what is 2.6 * 10^-2?

Answer 38

Remember, just take the decimal and move it two spaces to the left and add a 0.

Answer 39

give me one quick minute

Answer 40

2.60 ?