1) -15,28-(34,96)-(+24,15)-(-4,510+(-81,05)= (-15,28-34,96-24,15)-(-4,510+(-81,05)= -74,39-(-85,56)= -74,39+85,56=11,17;
2) -(+80,61)-23,49+(+64,045)-(-55,955)-(196,51)= -80,61-23,49+64,045+55,955-196,51= -104,1+120-196,51= 15,9-196,51= -180,61;
3) (-0,01)*(-0,3)*(0,05)= 0,003*0,05=0,00015;
4) -(-0,2)*(0,008)*(-0,01)*(-100)= 0,2*0,001*1=0,0016*1=0,0016