| 1248-289= |  + = | 7.7× = | 1÷ = | 1÷7+ = |
10- = | 3.14×102= | 11.7+3= | 2.75- = | 0.15÷0.3= |
| 4÷25%= | 35÷10%= | 2002÷22= |  ÷ = |  + = |
| 0.8-0.06= | 100÷99= | 4×25%= |  ：3= | 0.125×5×8= |
| 1248-289= | += | 7.7×= | 1÷= | 1÷7+= |
| 10-= | 3.14×102= | 11.7+3= | 2.75-= | 0.15÷0.3= |
| 4÷25%= | 35÷10%= | 2002÷22= | ÷= | += |
| 0.8-0.06= | 100÷99= | 4×25%= | ：3= | 0.125×5×8= |
千米=________米；教室面积大约70________；一支普通铅笔售价约50________．