Cost of 6 pens = $4.50 Cost of 1 pen = $4.50 ÷ 6 = $0.75 Cost of 10 pens = 10 × $0.75 = $7.50 Answer: $7.50 5. Quick Checklist for Students ✔ Did I write every calculation step? ✔ Did I label units ($, cm, kg, etc.)? ✔ Did I box/underline the final answer? ✔ Did I match sub-parts (a, b, c)? ✔ Did I check my working for errors? This shaping method works for any Maths 6A textbook (Oxford, Cambridge, Marshall Cavendish, etc.) and helps teachers see understanding, not just copying.