1. Drag the ones, tens and hundreds into their relevant columns to create a 1/2/3-digit number.[br]2. If 10 ones end up in the ones column then they will turn red. Click on the checkbox that appears in order to convert the 10 ones into a ten. This ten can then be dragged into the tens column as a carry. The values are adjusted accordingly.[br]3. If 10 tens end up in the tens column, then a similar process can be followed.[br]4. The Reset button will restart the process.