13乘(3.69-1.8)加111乘0.13
=13×(3.69-1.8+1.11)
=13×(4.8-1.8)
=13×3
=39
4.27-3.35加5.73-2.65
=4.27+5.73-(3.35+2.65)
=10-6
=4
2145-640除16乘25
=2145-40×16÷16×25
=2145-40×25
=2145-1000
=1145
13乘(3.69-1.8)加111乘0.13
=13×(3.69-1.8+1.11)
=13×(4.8-1.8)
=13×3
=39
4.27-3.35加5.73-2.65
=4.27+5.73-(3.35+2.65)
=10-6
=4
2145-640除16乘25
=2145-40×16÷16×25
=2145-40×25
=2145-1000
=1145