I could go through and answer it all and give you the answer but i think this will be better. Scientific Notation is just a way to sum up a long number so you don't have to write out a bunch of zeros. Without talking about "significant figures" you just put a decimal point after the first actual number, add a "x 10" then count the zeros and write the number as a superscript to the 10. any number like this 0.000.... (<em>smaller than 1</em>) has a negative superscript. any number like 10000... (<em>larger than 1</em>) has a positive superscript.
Example: 6,200,000 = 6.2 x 10^6 & 0.0000062 = 6.2 x 10^-6
Here are some general rules now that you know what you are trying to do:
1. Scientific Notation ONLY ever has ONE number in front of the decimal, like this: 6.02 x 10^23. NOT LIKE THIS: 60.2 x10^23 or 61.2 x 10^23 and NEVER a zero like this: 0.70 x 10^23.
2. it is ONLY ever a multiplication symbol, 6.02 "x" 10^23, NEVER divide, + or -.
3. for the examples on this paper, do NOT include zero's on the end like this 7.20 x 10^23. Only the actual numbers, and, <em>zeros that are</em> <em>between numbers</em> like this 6.0201 x 10^23. The zero's on the end get summed up and are noted in the ^23 part. (<em>This part is called a superscript, in case you didn't know that</em>)
4. In the last section they are just showing you some incorrect stuff to trick you up. Just put the decimal in the correct place and adjust the ^23 superscript bit.
OK. Alvi is incorrect because he didn't add the measures of all 3 angles of the triangle, whereas Brian did. So, Brian is correct and Alvi needs to work on that kind of problem.
