Math Manip Tip: Fractions on a Geoboard

A geoboard provides endless opportunities for fraction exploration. To increase your options, flip the tool over and use a dry erase marker on the back. Students can label, outline, write equations, and more!

Yesterday, I worked with a third grader who was struggling with fractions. Initially, it appeared that her greatest struggle was to understand the meaning of the numerator and denominator in relation to the parts. On a geoboard, she agreed that that this portion represented 1/2.

She then created the other half with another rubberband. I asked her if she knew what the 1 and the 2 represented in 1/2. She did not. So, on the geoboard, together we noticed the whole was divided into two parts and that each side represented 1 of those two equal parts. With a dry erase marker, she labeled each part.

I asked her if she could show 4 equal parts. She quickly did, and could tell me that each part was 1/4 of the whole.

Next, she made 8 parts and said that each portion was 1/8, labeling them. I asked how she knew that they were eighths. She said it was because there were 8 (equal) parts. We checked. With the dry erase marker! She then drew lines to represent sixteenths. We decided this was much easier than adding a lot more rubberbands.

After she noticed 8 equal parts make eighths, I asked her how many equal parts there are when there are fourths (4!), halves (2!! at this point she started grinning), thirds (3!! and grins harder, since we hadn't even attempted this one.)

It was time to wrap it up. I left her thinking about addition. For instance, if you have 1/4, how many more fourths do you need to equal 1 whole?


Using only a geoboard and a dry erase marker, we could repeatedly draw fractional parts, label fractions, count, erase, think again,...and more! If you haven't used a geoboard for fraction exploration--and written on it with a dry erase marker--you are going to love this!

Don't have a geoboard? Try the free online app from The Math Learning Center.

And for more fraction ideas, visit past blog entries.