autofilling formulas

hi was wondering if the is anyway to auto fill using a formula

this is what i want to do i have a loan that i pay x amount every month it is over 6 years.
so i have auto filled every month for the next six years now i want to fill in the formula so that it show the outstanding amount left to pay that month so for example lets say i have 5000 in a1 column to start and pay 100 per month. in a2 i have put the formula =a1-100
then in a3 i have put =a2-100 so is there anyway to auto fill this as i dont want to type it 60 times thank you in advance for your help

Hi k_babb;

You can actually just use the auto-fill for formulas as well. Select the A2 cell (which should contain =A1-100).

Move your cursor over the little box in the lower right, and it should change to a + sign. You can either double click it to auto-fill downward to the last row in the series (it will copy it down all the way to the last row in B), or manually click and drag the cursor downward to fill however many rows you want.

excellent thank you worked a treat