Elena Has Her Cake, and Eats It, Too

A Comparative Fractions Book

What’s that I smell?

What a yummy surprise!

Elena’s mom made a chocolate sheet cake!

I’ll just cut a little piece right from the middle.

That’s the best part.

Whoa, Little Missy!

Before you cut that cake, you’ve got to decide whether we should share it with the neighbors.

To share or not to share…

Well, if we don’t share, I’ll only be sharing the cake with Mom and Dad.

That’s just 3 people.

So, how many ways will we split it if we share with the neighobors?

4 Porterfields:Miss KathleenMr. DavidMadisonDawson

3 Towns-Schwartzes:Miss KathyMr. TimZack

3 Thuesens:MomDadMe

Let’s Compare

Well, getting 1/3 of a cake certainly looks like more than getting 1/10 of a cake!

But wait a minute… Madison and Mr. David don’t like chocolate cake… and Zach doesn’t like the pecans in the icing… I could have their pieces, too.

Let’s Compare

Hm. It’s hard to tell just by looking if 1/3 is any bigger than 4/10. I’m going to need to use some math.

Comparing Fractions

How can we compare thirds and tenths?We really can’t … we need to make them into the same sort of sizes. If we multiply each fraction times a form of 1, it won’t change the value.

1/3 X 10/10 = 10/304/10 X 3/3 = 12/30

Well, 12 of something is more than 10 of something. And I definitely want every bit of cake I can get. So, sharing it is!

Yes, I think 12/30 of this cake will do very nicely for me.

Let them eat cake!

You know, Mom, we really should share with our sweet neighbors.

It’s the right thing to do!

TEKS

• (3.2) Number, operation, and quantitative reasoning. The student uses fraction names and symbols (with denominators of 12 or less) to describe fractional parts of whole objects or sets of objects. The student is expected to:

• (A) construct concrete models of fractions;

• (B) compare fractional parts of whole objects or sets of objects in a problem situation using concrete models;

• (C) use fraction names and symbols to describe fractional parts of whole objects or sets of objects; and

• (D) construct concrete models of equivalent fractions for fractional

parts of whole objects.