What is the scientific notation for 12400000?

Start with the natural placing of the decimal in 2400 at the end: 2400. Move it over to make a number between 1-10 (but not including 10 itself): 2.4 You will take this number and always multiply it by 10: 2.4 x 10 Since you moved the decimal 3 places to make 2400 become 2.4, you will add the exponent 3 to the multiplier 10, giving you the final answer: 2.4 x 103