55-3 = 52
52÷4 = 13
13+1 = 14 组
1+(-3)+5+(-7) 、、、、+(-55)=?
= -2 - 2 -2 -.-2 一共有 14组
= -2 x 14
= - 28256*（0.125）-12.5*13.5+0.125*3980=？256*（0.125）-12.5*13.5+0.125*3980= 256 x 1/8- 1/8x1350+1/8 x 3980= 1/8x(256 - 1350 + 3980)=360.75