1. 210/10=21
21*9=189
1:9=21:189
2. 210/7=30
30*2=60
30*5=150
2:5=60:150
3. 210/7=30
4*30=120
3*30=90
4:3=120:90
1. 210/10=21
21*9=189
1:9=21:189
2. 210/7=30
30*2=60
30*5=150
2:5=60:150
3. 210/7=30
4*30=120
3*30=90
4:3=120:90