77-53=24, 24+28=52, 400×8=3200, 3200-700=2500,
52+19=71, 97-43=54, 56÷7=8, 320+300=620,
34+56=90, 600×8=4800, 34+8=42, 700+900=1600,
45+37=82, 3000×4=12000, 92-6=86, 47+35=82,
4
7 +
2
7 =
6
7 ,
5
6 -
1
6 =
2
3 ,
5
6 +
1
6 =1, 1-
2
5 =0.6.
77-53=24, 24+28=52, 400×8=3200, 3200-700=2500,
52+19=71, 97-43=54, 56÷7=8, 320+300=620,
34+56=90, 600×8=4800, 34+8=42, 700+900=1600,
45+37=82, 3000×4=12000, 92-6=86, 47+35=82,
4
7 +
2
7 =
6
7 ,
5
6 -
1
6 =
2
3 ,
5
6 +
1
6 =1, 1-
2
5 =0.6.