Question

Hey so I've been having trouble with this question for a while. I know the answer has 5 significant figures but what I don't know is which one is correct. I tried a few methods to get to what I what but I just keep confusing myself. Can anyone give me a hand with this? I'm not asking for you to give me the answer I just need a little guidance so I can get it on my own please.

What is the correct answer using significant figures?
1.2x103 * 787=?
a. 9.44 x 103
b. 944
c. 944400
d. 9.4 x 105

Answer 1

@Vocaloid

Answer 2

5 significant figures? are you sure about that?

Answer 3

um well now im not...

Answer 4

This is sig stuff is my only weakness with chemistry i really dont get it

Answer 5

also, is 103 supposed to be 10^3, like with a 3 in the exponent?

Answer 6

yea

Answer 7

well, ok, first we just multiply the numbers together to get

944400

now, the rule for multiplication is that: the number of sig figs in the answer = the lowest number of sig figs in the factors (I'll demonstrate)

Answer 8

1.2 * 10^3 has 2 sig figs (both 1 and 2 are significant)
787 has 3 sig figs

so the answer will have 2 sig figs because 2 is the smallest number of sig figs

Answer 9

thats where my first mistake was!

Answer 10

I put all of them together by accident

Answer 11

right, remember it's the smallest number of sig figs

so, we rewrite 944400 in scientific notation to get

9.44400 * 10^5

then round down to 2 sig figs

9.4 * 10^5

Answer 12

So the answer would be D

Answer 13

yup

Answer 14

Wow
Thank you so much for your help!