Most research articles need units. When it comes to scientific writing, style guides ask authors to use unit symbols and discourage them from spelling out the actual unit (e.g., m instead of meter). Another common dilemma that researchers face is whether or not to include a space between a numerical and its corresponding unit. As per the convention, a space must always be included between numericals and their corresponding units. Missing the space between the numerical and the unit actually alters the meaning. However, as per the convention, authors need to omit spaces between numbers and degree or percent symbols.
Incorrect: The road is 20m wide.
Correct: The road is 20 m wide.