1.6+3.8= 0.5+0.9= 4.6+4.3= 2.9+6.1=
0.25+0.34= 0.36+0.45= 0.72+0.18= 0.59+0.41=
3.8-1.4= 0.9-0.5= 4.6-4.3= 6.1-2.9=
0.37+0.15= 0.95-0.36= 0.43-0.38= 0.51-0.41=
17.49+6.3= 20.6-16.8=
①67.73+39.67= ②★59-28.19=
7元零8分﹣3元9角
3km50m+750m
10kg﹣2kg650g