Categories
Decimals Fractions Numbers & Operations -- Fractions

A 4th Grader Who Prefers Decimals to Fractions

IMG_3251

 

This student — let’s call her Alice — is in 4th Grade. She did some work with fractions in 3rd Grade, but clearly isn’t comfortable with them.

I went over to Alice and noticed that she wrote “0.5” for point A. I asked her to read that number, and she said “a half.” Then I drew a half-filled circle and I asked Alice to tell me what fraction of the circle was filled in. She said “a half.”

Me: Can you write “a half” as a fraction?

Alice: Why do you have to? This way is so much easier.

[I show her how I write a half.]

Alice: Oh, a one and a two.

[I draw two more circles, one with a quarter filled in, the other with three quarters filled in.]

Me: What part of the circle is filled in in these two circles?

Alice: A quarter. Three quarters.

Me: How would you write those numbers down.

Alice: Umm…so this would be one-four?

Me: Yes, though I’d read this as one-fourth.

Alice: And this would be one-three.

This is interesting in all sorts of ways. First, because you can really see in Alice’s work the difference between written and spoken language. Alice can tell you what a half is. She can even tell you how much is shaded in on the other circles, but she can’t write it. Attention needs to be given to both verbal and written language, and we teachers tend to focus on our students written work.

Also, “one-four” and “one-three”? That’s so interesting. Alice sees “three” as the most important part of “three quarters,” and tentatively thinks that fractions are just always “one-something.” That’s a pretty strong tell.

The other remarkable thing is how strongly Alice prefers decimal representations to fractions. Alice showed this preference consistently in her problem solving.

IMG_3252

 

The kindly Professor Danielson argues that, in a curriculum, fractions ought to precede decimals. But it’s also true that decimals are addictive. In my high school classes, kids use their calculators to transform fractions to decimals as a defensive measure. You know the easiest way to help (most) kids solve equations with fractions? Point out that they can convert those fractions to decimals.

Decimals are absolutely enticing to people, even to this kid who is just getting started in this whole mess.

4 replies on “A 4th Grader Who Prefers Decimals to Fractions”

I wonder if any of the below language would be helpful for her to transition from “one-four” to “one-fourth”
“one piece, where four equal pieces make a whole”
“one, where four makes a whole”
“one out of four”

As a first grade teacher I think a lot about the language in order, at least attempt, to not set up misconceptions later. Like Avery said, the language ‘one out of four’ or ‘three out of four’ might be a good place to start. We even showed our first graders the notation with those words – we wrote the one on top, drew a rectangle for the line in the fraction and wrote ‘out of’ in it, and then wrote the four on the bottom.

I’ve read (but can’t remember) that some other languages are more explicit in calling their fractions. I know in Vietnamese, 1/4 is “mot phan tu,” which literally says one part four; 2/3 is hai phan ba. Saying the word “part” after the numerator seems to help?

One out of four has some dangers associated with it too, because then you start thinking that improper fractions can’t be fractions (that, I think, is the point behind the verbiage in the CCSS grade 3 fraction standards)

Comments are closed.