240道脱式计算题(六年级)

3/7 × 49/9 - 4/38/9 × 15/36 + 1/27 12× 5/6 – 2/9 ×3 8× 5/4 + 1/46÷ 3/8 – 3/8 ÷64/7 × 5/9 + 3/7 × 5/9