Ms. Cruz had an overdraft charge on her checking account, so she owed
the bank $40.57. If she wants to get her checking account back up to
$200.00, How much money does she need to deposit?

487.9573 * 1000 = 487947.30

As you can see, the first number has a decimal point, and the second number is 1000. You can drop the 0s in the 1000 leaving 1 to multiply with the first number. Simply move the decimal point to the right based on the number of 0s there are on the second number.

Since, 1000 has three 0s. Move the decimal point 3 times to the right of the number. So, from 487.9573 to 487957.3

If the function is division but the numbers are the same, you must move the decimal point to the left.