The spreadsheet editor is readonly unfortunately. Please be advised if you select several vertices and type a value in the transform panel field, it will not set the vertices values to that number, but it will set the median of the values to that number. eg in your case I doubt if you type 150 in the x field all the vertices will be at X = 150. A workaround is to scale all selected vertices along the axis you want to set the number to and set the scale value to 0, THEN change the value.
Comments
You can type a value into the item settings in edit mode:

The spreadsheet editor is readonly unfortunately. Please be advised if you select several vertices and type a value in the transform panel field, it will not set the vertices values to that number, but it will set the median of the values to that number. eg in your case I doubt if you type 150 in the x field all the vertices will be at X = 150. A workaround is to scale all selected vertices along the axis you want to set the number to and set the scale value to 0, THEN change the value.
Cheers
I don't know if this is what you're looking for, but you can use vector math ceil or floor to round.
