2.05-0.81÷2.7×四又二分之一
=2.05-0.3×4.5
=2.05-1.35
=0.7
7.6×7.6+7.6×一又五分之二+7.6
=7.6×(7.6+1.4+1)
=7.6×10
=76
87.58-(7.58-3.8)
=87.58-7.58+3.8
=80+3.8
=83.8
3.14×一又八分之三+3.14×八又八分之五
=3.14×(1又3/8+1又5/8)
=3.14×3
=9.42
2.05-0.81÷2.7×四又二分之一
=2.05-0.3×4.5
=2.05-1.35
=0.7
7.6×7.6+7.6×一又五分之二+7.6
=7.6×(7.6+1.4+1)
=7.6×10
=76
87.58-(7.58-3.8)
=87.58-7.58+3.8
=80+3.8
=83.8
3.14×一又八分之三+3.14×八又八分之五
=3.14×(1又3/8+1又5/8)
=3.14×3
=9.42