Split the 15 pies into 3 equal units. Two of those units were sold.

15 pies555sold = 2 units

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

  1. 3 units → 15
  2. 1 unit → 15 ÷ 3 = 5
  3. Sold = 2 units → 2 × 5 = 10

10 pies were sold.

Check: 2⁄3 of 15 = 10. ✓