18×502=18*(500+2)=18*500+18*2=9000+36=9036
84×101 =84*(100+1)=8400+84=8484
35×14=25*2*7=70*7=490
31×(200+5)=31*200+31*5=6200+105=6305
(200+5)×13 =200*13+5*13=2600+65=2665
102×16 =(100+2)*16=1600+32=1632
18×502=18*(500+2)=18*500+18*2=9000+36=9036
84×101 =84*(100+1)=8400+84=8484
35×14=25*2*7=70*7=490
31×(200+5)=31*200+31*5=6200+105=6305
(200+5)×13 =200*13+5*13=2600+65=2665
102×16 =(100+2)*16=1600+32=1632