Math IS Real Life: July 2018 Edition – Double and Half to create a quick design

This It’s the first Wednesday of July which means it’s time for our monthly linky – Math IS Real Life!! If you want to see how the linky works, or just want other real world math ideas, check out our Pinterest Board of all the posts so that you can look back and find some great ideas and REAL pictures to use in your classroom!

If you are linking up, please include the below picture to link back to this blog post


 A monthly REAL WORLD math blog link-up hosted by MissMathDork,


This past weekend I fell in love with a jellyroll that would be perfect for a quilt for one of my friends.  Other than being the perfect color and design it was also on sale – win, Win, WIN! It was such a great deal that I bought two!!

Seeing as it was a holiday weekend and I had some spare time, I wanted to work on making a pretty simplistic design to fit my friend’s aesthetic.

 I did some research (aka searched YouTube for videos) and found a fun, quick, and nice looking design call the Jelly Roll Race. The basic gist of the quilt is you sew all the jelly roll strips (40 strips — 44 inches long by 2.5″wide) together end to end. This creates one long length of strips that is approximately 1600 inches long.

Then, you match the two ends, fold the long length in half and sew together leaving you with a length of approximately 800 inches that is now 4 inches wide (plus another 1/4 in on each side for seam allowance).

Then you cut the fabric in half at the fold…. and repeat the process. The next length will be approximately 400 inches long and 8 inches wide.

Rinse and repeat….

Approximately 200 inches long by 16 inches wide

Because the “rinse and repeat” steps made it a bit too easy to fall into a mindless stupor, I decided to write out the math so that I could mentally check where I was with each fold and sew step.

I didn’t really want to go as small as 50 inches (I really like a large blanket to snuggle in) but the other option was to be 100 inches which is way too wide for a couch blanket.  I had planned on using both jellyrolls but that would have given me approximately 3200 inches of fabric in a length and I still would have ended up with 100 inches or 50 inches wide unless I cut off a lot of excess.  I opted to just make 1 jellyroll worth of fabric, and then I’ll build up the perimeter using borders and the other jellyroll. 

After the initial fold and sew of 800 inches, the sewing became much faster.  Each round took half as long to sew.  At this point it occurred to me that this is a great visual for the multiplication strategy of doubling and halving (32 x 20 = 64 x 10).  You start with an amount of fabric – you make it all one length, then you double the width when you half the length.  You keep going and the amount of fabric stays the same.  You could also use this for a nice visual of area – composing and decomposing (you would have to take the seams on the back into account if the students were physically measuring the fabric strips on the face of the quilt).  This could be a really fast, and easy (and relatively cheap!) project to bring into classroom.  You could even have all of your students sign on the quilt face when complete to create a classroom quilt.

Above (16 wide – 32inches – by 100 inches long)

Above (32 wide – 64 inches – by 50 inches long)

I haven ‘t come up with an idea for the border yet, but again, great conversation about area and perimeter.  I think my plan will include multiple borders to really add some width and bulk to the quilt.  More pics to come once I’ve come up with a plan. Perhaps there will be an update in August 🙂

I hope you all had a wonderful holiday weekend!  <3 you all


  Don’t forget to check out the other MIRL posts below!  Check back over the next few days – more will be added!!

Categories: #mirl, computation and estimation, geometry and measurement, hands-on math, math is real life, mental math, number and number sense, and patterns, functions and algebra.

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