1. We can get together first. It is not difficult to draw that the cube of 2730 and 14 is very close, and 2730/ 14= 195.

195= 13* 15. These three numbers are 13, 14 and 15 respectively. If you are a middle school student, you can set, n- 1, n+ 1.

2. Let k, k+2, k+4 and k+6(k is an odd number). k/k+6= 19/2 1。 k=57。

These four numbers are 57, 59, 6 1 63. Add up to 240.

3. 13 13 13/979797= 13/97, 130 130/970970= 130/970= 13/97.

1300 1300/97009700/ 1300/9700= 13/97.9797/ 13 13=97/ 13

The above formula = (13/97+13/97+13/3) ÷13 ÷ 97 * 97 ÷13.

=3*93/ 13