1.25*2.5*8*12
= (1.25*8)*(2.5*4)*3
= 10*10*3
= 300
3.8*99+3.8
=3.8*(99+1)
=3.8*100
=380
2.78*7.8+2.78*3.2-2.78
=2.78*(7.8+3.2-1)
=2.78*10
=27.8