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