Write number in expanded form , one mullion, three hundred forty five thousand, eight hundred twenty

scientific notation can be used to turn 0.0000073 into 7.3 x 10^-6.

first, move the decimal place until you have a number between 1 and 10. if you keep moving the decimal point to the right in 0.0000073 you will get 7.3.

next, count how many places you moved the decimal point.

in this case you moved it six times so you put down a 10 after the x , then the 6 to the left of the 10, because it was a decimal you make it a negative 6. your outcome would be 7.3 x 10^-6.