↓ 9/10 − 4/6 ↓
↓ =9/10 − 4/6 ↓
↓ =9/10 + −4/6 ↓
↓ =9/10 + −2/3 ↓
↓ =27/30 + −20/30 ↓
↓ =27+−20/30 ↓
→ =7/30 ←
(Decimal: 0.233333)
