Make each “leftover” the unit. Jerry used 3⁄4, so his money is 4 equal units (1 left). Tom used 5⁄6, so his money is 6 equal units (1 left). Both leftovers are equal — that is why the units match across the two bars.

JerryleftspentspentspentTomleftspentspentspentspentspent$100 total

Plain numbers are given; italic underlined numbers are worked out.

  1. Jerry + Tom → 4 units + 6 units = 10 units → $100
  2. 1 unit → $100 ÷ 10 = $10
  3. Each leftover → 1 unit = $10

Each of them had $10 left.

Check: Jerry $40 (1⁄4 = $10 left), Tom $60 (1⁄6 = $10 left); $40 + $60 = $100. ✓