第一题:
4.15-3.75×10%-5/8
=4.15-0.375-0.625
=4.15-(0.375+0.625)
=4.15-1
=3.15
第二题:
1-39%×1/2÷0.195
=1-0.195÷0.195
=1-1
=0
第三题:
8×40%+2/5÷1/2
=8×0.4+0.4×2
=(8+2)×0.4
=4
第一题:
4.15-3.75×10%-5/8
=4.15-0.375-0.625
=4.15-(0.375+0.625)
=4.15-1
=3.15
第二题:
1-39%×1/2÷0.195
=1-0.195÷0.195
=1-1
=0
第三题:
8×40%+2/5÷1/2
=8×0.4+0.4×2
=(8+2)×0.4
=4