Math: Pen vs Pencil

Many math students are given strict instructions by their teachers to do all their work in pencil. I disagree.

The advantage of doing work in pencil is that:

  • it is easier to erase, so students are less likely to be paralyzed by “I am not sure this is correct, so I don’t dare write it down”

The disadvantages of working in pencil are that:

  • writing has less contrast with the page (easier to miss negative signs & exponents)
  • after repeated erasures, the page is hard to read
  • pencils often need sharpening, making writing harder to read
  • the lead in mechanical pencils breaks often, adding a distraction

The disadvantages of working in pen are:

  • many pens can leave blobs of ink on the page after drawing a line
  • you cannot erase your work (use scrap paper to solve this)

The advantages of working in pen on scrap paper are:

  • higher contrast writing makes it harder to miss small symbols (fewer errors from overlooking something)
  • no time outs needed to sharpen or extend lead needed
  • much less time spent erasing (cross it out with one line and move on)
  • less mess from eraser shreds

If I have a choice, I do all of my math work on scrap paper in pen. I then copy my final results over, either into my computer or onto the paper I intend to submit. Copying my work over has helped me figure out more math topics than any other activity, as it gives me another opportunity to:
– think through the problem
– consider alternative approaches to solving it
– verify I have not made arithmetic or algebraic errors
– edit my solution to make it as clear and convincing as possible

By Whit Ford

Math tutor since 1992. Former math teacher, product manager, software developer, research analyst, etc.


  1. One of my colleagues (at a community college) insists on pencil. I would hate that. I hate writing with pencil because it gets on my hand. (I am left-handed.) I cannot use mechanical pencils – the lead breaks or slip inside constantly.

    Like you, I write in pen, and rewrite the problems. I too learn more that way.

  2. I agree. Pen, pencil, whatever, as long as you’re trying and showing your work. I think I’m in the minority of Math teachers on this topic. Many kids think of their math teachers as very picky. I try to be more relaxed and go with the flow, as much as possible.

  3. Agreed. Math is an artful topic, but the calculations and musings of math need not be perfect, beautiful, or even neat, at times. I like pens because they glide smoothly and provide a more pleasing tactile experience, but pencils are sometimes the gritty experience I need in order to wring out the most from a distracted brain. Use the tool that best meets your current greatest need.

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