2. Secondly, prepare a pen for writing and open the math exercise book. Write 1000 first, and then write 108 below. You must align the same digits, so the zeros of each digit should be aligned, the zeros of the tenth digit should be aligned with the zero of the minuend, and the zeros of the hundredth digit should be aligned with the eight of the minuend. Draw a horizontal line below, starting from the number of units.

3. Finally, draw a horizontal line below, and you can start from the unit.