5.21-3.79=( )
5.6+3.1= 6.6-6.4= 5.09-0.09=
0.24+0.32= 7.9+2= 32+0.5=
2吨50千克+630千克=
5.15+0.5= 9.8-4.8= 8.3+0.07= 0.66-0.6=
0.94-0.54= 4.3-3= 0.08+0.2= 10+0.97=
2.36+0.64= 7.08+0.01= 4.65-0.25= 6+3.4=
5.68+0.32= 1.25+0.8= 2.5+4.5= 0.82-0.42=