Math Question

[Liriel]

Problem in my book reads:

6.44x10^-4 + 9.23x10^-3 + 7.57x10^-2 + (8.82x10^-3) x (4.67x10^-2)

The answer given is 4.97x10^-1.

I keep getting something different (8.60x10^-2).

Is there a typo or am I making some mistake that I can't find right now? :smallfurious:

[Brother Oni]

Assuming you meant (8.82x10-3 * 4.67x10-2) for the last part, I'm getting the same answer as you (8.60x10-2).

[averagejoe]

Google agrees. (https://www.google.com/search?q=calculator&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#sclient=psy-ab&hl=en&client=firefox-a&hs=7mi&rls=org.mozilla:en-US%3Aofficial&source=hp&q=6.44*10^-4+%2B+9.23*10^-3+%2B+7.57*10^-2+%2B+%288.82*10^-3%29*%284.67*10^-2%29&pbx=1&oq=6.44*10^-4+%2B+9.23*10^-3+%2B+7.57*10^-2+%2B+%288.82*10^-3%29*%284.67*10^-2%29&aq=f&aqi=&aql=&gs_sm=e&gs_upl=1139l1139l2l1848l1l1l0l0l0l0l233l233l2-1l1l0&bav=on.2,or.r_gc.r_pw.,cf.osb&fp=27334aec636ec0d8&biw=1280&bih=615) Are you sure you transcribed it correctly?

[Liriel]

Yup, that's exactly what I meant.

Thanks. Good to get confirmation.



The long way out it is written as:

A+B+C+DF

A = 6.44x10^-4
B = 9.23x10^-3
C = 7.57x10^-2
D = 8.82x10^-3
F = 4.67x10^-2

or on the next line exactly as I put in the OP.


Edit: I should also add that 'book' means the handout book written by the prof.

[Illieas]

Yup, that's exactly what I meant.

Thanks. Good to get confirmation.



The long way out it is written as:

A+B+C+DF

A = 6.44x10^-4
B = 9.23x10^-3
C = 7.57x10^-2
D = 8.82x10^-3
F = 4.67x10^-2

or on the next line exactly as I put in the OP.


Edit: I should also add that 'book' means the handout book written by the prof.

if you wrote it out perfectly. then your professor messed up.

your professor is looking for 4.97*10^-1

when the maxing out only nets you at best
.0999+.00999+.000999+.0000999= 1.109*10^-1

maybe a there is decimal in the wrong place or exponent mistake

[Teddy]

Edit: I should also add that 'book' means the handout book written by the prof.

This probably explains quite a lot. Being a maths professor is in no way a guarantee against common misstakes and thought errors, and if I get the concept of "handout book" right, it's most likely not especially proof-read either.

[Keld Denar]

Note that due to order of operations, the parenthasis here:

(8.82x10^-3) x (4.67x10^-2)

are superfluous. Thats basically A*B*C*D, which is the same as (A*B)*(C*D) and (A*B*C*D), and (A)*(B)*(C)*(D) and A*(B*C*D).

Some teachers might mark you down for having superfluous parenthasis in your final answer, citing that it isn't in its "most simplified form".

Just a friendly PSA.
http://4.bp.blogspot.com/-7UyesaqfeFM/TmUTMYv0IiI/AAAAAAAAANE/lxclINENzkE/s1600/TheMoreYouKnow.jpg