Her pocket money is 6 equal units. One unit was used on lunch, so 5 units ($10) are left.

Pocket money$2$2$2$2$2$2left $10 = 5 units

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

  1. 5 units → $10
  2. 1 unit → $10 ÷ 5 = $2
  3. Pocket money = 6 units → 6 × $2 = $12

She had $12 pocket money.

Check: used 1⁄6 of $12 = $2; $12 − $2 = $10 left. ✓