Posted by matthew on Sunday, March 7, 2010 at 4:29pm.
Your number is 25,000,000. In scientific notation, you never show more than the ones place in your answer and every number has a decimal point - even if you don't see one. If you don't see one, it is on the right-hand side. Therefore, your number is actually 25,000,000. with a decimal at the end. Now count the numbers to the right until you have one number left - the 2. You moved seven places. Place the decimal there to get 2.5. Next, to get to the original number again, you would have to multiply 2.5 by 10,000,000, or 10^7 power (the number of spaces you counted). Therefore, your answer is 2.5 x 10^7
2.5×10^7