The Power of a Paper Towel: Fun with Grandkids

The Power of a Paper Towel: Fun with Grandkids

The Power of 2

Here’s another way to learn about fractions and fractional equivalents as well as an introduction to how a computer counts.

Reczniki papierowe

Paper Towel (Photo credit: Wikipedia)


  • Paper towel or paper napkin
  • Magic marker (pens and pencils are ok, but may tear the paper)


  • Have your grandchild fold a paper towel in half.
  • Have them press down on the fold to make a neat fold line that is easy to see.
  • Have them unfold and draw along the fold line with a magic marker
  • Have them count how many sections the paper towel has now (2 sections)
  • Ask your grandchild what fraction or part of the whole towel is one section (one-half)
  • Fold the towel in half again, then, fold in half again. Press down on folds.
  • Open up the towel and draw along the fold lines.
  • Have them count how many sections of the towel there are now (four).
  • Ask your grandchild what part of the towel is one section (one-fourth).
  • Ask your grandchild what part of the towel is two sections (two-fourths or one-half).
  • Refold the first two folds and fold in half again. Unfold and draw lines on the towel. They will now have 8 sections.
  • One section is one-eighth. Two are one-fourth of the towel. Four are one-half of the towel.
  • Refold and fold in half again. When you open up the towel and draw all the lines, you will have sixteen sections.
  • One section is one-sixteenth. Two is one-eighth. Four is one-fourth. Eight is one-half.

What Should Happen?

Before their eyes, your grandchildren will see how a whole can be divided into even pieces. They are seeing another way to show that some fractions are equivalent. Two-fourths, for instance, is the same size as one-half of the towel.

They are also being introduced to an important concept in computers, the sequence, 1, 2, 4, 8, 16, or the power of 2. That is, each time your grandchild folds the towel in half again, they are doubling the number of sections in the towel. Computers work by testing whether a circuit is on or off. So, the only numbers available to work with are 0 (off) and 1 (on) and arithmetic with those two numbers.

Computer memory is measured using a binary, or two numbers, numbering system. Starting with a byte, for 8 bits (a bit is one of those circuits that is on or off), memory is measured by kilobyte, or, roughly one thousand, but, more accurately, 1,024 bytes, or megabytes (approximately one million bytes or 1,048,576), then gigabytes (one billion) and terabytes (one trillion).

Eventually, your grandchildren will start learning about exponents. They tell us how many times a number is multiplied by itself. 2 to the power of 1, for instance, is 2 x 1 which equals 2, or 21 . 2 to the power of 2 is 2 x 2 which equals 4, or 22. 2 to the power of 3 is 2 x 2 x 2 which equals 8 or 23.

This is important in the computer field because 2s that are multiplied a lot get unwieldy. Thus, we shorten 1,024 to 1K (rounding off to 1,000, where K, or kilo, means 1,000). But, 1K is also 2 to the power of 10, or 2 multiplied by itself 10 times, or 210. That is the power of 2.

And, you thought it was just a paper towel.

Thanks to for this suggestion.

Carol Covin, Granny-Guru, Author, “Who Gets to Name Grandma? The Wisdom of Mothers and Grandmothers”

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Comments (10 )

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  1. Leora says:

    Clever ways to use a paper towel! I wonder if my daughter would accept my exercise or moan and groan.

  2. Interesting information about computer math. I have known about the binary language of computers but not the counting in 2s. I always wondered why 1024 was a Kilobyte instead of 1000.

    • carolcovin says:

      Jon, it's strange until you find out why it makes perfect sense. My son is in computers, so when I was demonstrating the concept with my grandson this weekend, I said, and your Dad is going to recognize this sequence of numbers and he had to laugh.

  3. JeriWB says:

    I did a similar folding exercise with students when it came to getting the point across about Shakespeare's folio and how pages are folded to make books.

    • carolcovin says:

      That is clever, Jeri. Most people who have not printed a book know nothing about folios. You gave your students a tremendous gift.

  4. findingourwaynow says:

    I love that you can take something so ordinary and turn it into a great and extraordinary lesson. This is such a great way to demonstrate fractions. It using three senses, touch, sight, sound. This only enhances the learning. Very well done. 🙂

    • carolcovin says:

      Thank you! Only Grandmas have time to do this sort of thing. Moms and teachers are busy with so many things they have to do and teach in a short period of time.

  5. carolcovin says:

    So, I'm demonstrating this concept to my grandson when my son and daughter-in-law are over for dinner. My DIL, an accountant, gets into the math immediately, marks the sections as they are unfolded, and then tears two of the sections off to show how they fit in the larger section. Don't you love Moms!

    • carolcovin says:

      She marks the section with the appropriate fraction. Later, she came up with the idea of drawing on the lines in different colors, so it would be easier to reconstruct 1/2, 1/4. 1/8. Gotta love people who take an idea and run with it!