EXCEL upper left corner of the comma

I have a document there is a EXCEL do not know why, not a comma on the surface, the mouse can be found at the bar inside the top left corner of each cell has a comma, why? How to destroy it!

it is normal to enter some data to make it into a text format, such as the calculation does not take part on the tube unnecessary, To be their choice, right-format, full conversion to digital.If you are not out to the data, select the column, then “delete” button to remove all agree that the upstairs, to add two points:
1, first select a cell
selected in the top left corner of any error indicator of the green cells in the cell next to, click the button appears, and then click “into a digital”.
2 .
A selected region as a whole in the blank cell, enter the number 1.
Selected cell and the “Edit” menu, click “copy”.
Selected to be converted for storage The scope of the digital text.
In the “Edit” menu, click “Paste Special”.
In the “operations”, click the “x”.
Click “OK”.
To delete the first step in the type of cell.That is because the net figure out is, you change the text you out.Nothing normal!