## Wednesday, July 1, 2009

### Practice problems for the test on 7/2

The Transformers sequel made \$108,966,307 this weekend.

a) Round this number to one significant digit.
b) Round this number to two significant digits.
c) Round this number to three significant digits.

According to the calculator 50! rounds to 3.041 x 10^64 and 60! rounds to 8.321 x 10^81, both rounded to four significant digits. Find the following values.

d) 50! / 60!
e) 60! / 50!
f) 50! x 60!
(note: the calculator will tell you overflow error on problem f because it doesn't like numbers bigger than 10^100 power. You will have to do this one by hand.)

Prof. Hubbard said...

The Transformers sequel made \$108,966,307 this weekend.

a) Round this number to one significant digit.
\$100,000,000

b) Round this number to two significant digits.
\$110,000,000

c) Round this number to three significant digits.
\$109,000,000

According to the calculator 50! rounds to 3.041 x 10^64 and 60! rounds to 8.321 x 10^81, both rounded to four significant digits. Find the following values.

d) 50! / 60!
3.655 x 10^-18

e) 60! / 50!
2.736 x 10^17

f) 50! x 60!

(note: the calculator will tell you overflow error on problem f because it doesn't like numbers bigger than 10^100 power. You will have to do this one by hand.)
3.041 x 8.321 = 25.304161 or changed to scientific notation, 2.530 x 10^1

10^64 x 10^81 = 10^(64+81) = 10^145

Combining the two parts,

50! x 60! = 2.530 x 10^146

Anonymous said...

can we go over d-f in class..i am a bit confused, and do not have much practice with this.

Prof. Hubbard said...

Sure. We can discuss this on Thursday.