Fraction Number Strings

Using number strings to get the fifth graders to add unlike denominators in their head.We are knee deep into our fractions unit and I wanted to share something that has been rather successful in getting my students to recognize landmark fractions and decimals:  Number Strings.

What are number strings, you ask?  Well, they are similar to number talks in that it is a way to get the kids to *mentally* think about the math that they are doing.  What makes them different is that the number strings focus on ONE strategy to get the students solving problems, as opposed to the several strategies that number talks promote.

Since we are working on adding and subtracting fractions, my math coach gave me this book Minilessons for Operations with Fractions, Decimals, and Percents: A Yearlong Resource (Contexts for Learning Mathematics) to help me get started.  The first number string that is presented shows the kids how to equate certain fractions with money.  Money is so common amongst the kids, that they instantly related.  Showing the kids that 1/2 is just like $0.50, or two quarters....well, they get it.  Then you tell them that 1/4 is like $0.25 or 1 quarter.  Bingo...lightbulbs.  So if you add 1/2 + 1/4 it is like adding $0.50 and $0.25.  That is $0.75, or three quarters....3/4!  Boom!

Once you show them that, you do another problem, this time with 3/4 + 1/2. Since they already know those landmark decimals, it isn't too hard.  $0.75 + $0.50 = 5 quarters or $1.25 or 1 1/4.

This was our first number string.

Using number strings to get the fifth graders to add unlike denominators in their head.
I promise you, ALL of this was done in their head.  All of it.  I just wrote down what they said.

The next day, we added 1/5 in there.  1/5 = $0.20.  And 1/10, which was $0.10.   And 1/20.  When I asked my students what they thought 1/20 was, there was literally no hesitation.  Hands went up all around saying $0.05.

Then, we did mixed numbers and improper fractions.

Then subtraction.

Seriously, these are amazing.  The kids are adding fractions with unlike denominators IN THEIR HEADS!!  I can not believe it.  There has been a shift in the way that they even think about fractions.  Equating them to decimals naturally really has made all of the difference in the world.

Now this is only the first strategy that the number strings book presents. There are MANY, MANY more.  They truly are fantastic.  If you already do number talks, this is a must to add.

A great website to check out is Number Strings.  There are so many great ideas there too!

Do you do number strings?  Do you have any advice you care to share?


  1. I love this. I will definitely be sharing this with my 5th grade teachers! Did the book have anymore good mini lessons? I might have to purchase it as a resource!

  2. You help a lot! Whenever I read your blog I find out something new for me and easy ways to solve problems. I think that other students find your blog useful too. However there are always students who consider Maths as something extraordinary for their minds to be acquired, actually vast majority of students consider exact sciences to be difficult, that is why in most cases they do not do homework on their own, but use services of EssayDune company at But it is a big pleasure to learn new things that may serve useful with studies. Thank you!

  3. I love how basic, yet higher level this is. Students can really get a great number sense from this activity!


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