Start from the end first. Draw the model with Ahmad having twice as many as Tom. Indicate 2 units for Ahmad and 1 unit from Tom. The units are very important to help us calculate later.

Then, we work backwards. Cut away 60 from Ahmad and give back 60 to tom. We can draw a 60 in Ahmad’s model by drawing the dots up. Then we also know that Ahmad had 80 more originally. Remember that the 60 (in purple) is taken away so the extra 80 ends where the 10 taken away begins.

Use the units to solve the remaining math. Hope it helps!