Start with 3900 points, take away the 1600 she spent, then add the 850 she gained.

3900+850used 1600

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

  1. After buying → 3900 − 1600 = 2300
  2. After gaining → 2300 + 850 = 3150

June has 3150 points now.

Check: 3900 − 1600 + 850 = 3150. ✓