Most of us have glass gems sitting around the house. (Don’t have any? See where we got them super cheap below!) These glass gems came in handy when we were practicing first grade math recently. Math and common core standards can be a tricky thing with terms like composing and decomposing numbers. They can throw us old moms and dads for a loop when we are helping out with homework duty (or following guidelines in homeschooling curricula). Today’s post for our 31 Days of Learning with Free (or almost free) Materials was a fun and easy way to practice difficult first grade math concepts in a fun way!
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How do you Compose and Decompose numbers (First Grade Math):
To start with, we used clear glass gems
that we found in the dollar store. You can get a pound of gems for a dollar which will go a long way in math and other activities with the kids. You can quickly purchase the gems here for convenience.
that we found in the dollar store. You can get a pound of gems for a dollar which will go a long way in math and other activities with the kids. You can quickly purchase the gems here for convenience. What is “composing numbers”?
To practice our composing and decomposing of numbers, we pulled out a handful of the glass gems and paper with a marker. I drew a triangle and wrote two numbers in two corners of the triangles. My oldest daugher (in first grade at the time) used the gems as counting manipulatives. She added the two numbers up by counting the glass gems and wrote the total in the empty corner of the triangle. This adding numbers together, or building a number is called composing a number. Another way to say composing numbers is to think about putting numbers together. My daughter came home from school talking about how to “put together” numbers.
What is “decomposing numbers”?
To decompose the number, we wrote another triangle and started with a higher number and a lower number. She used the clear glass gems to subtract by counting out the manipulatives. This taking apart of a number is called decomposing a number. You can think about decomposing numbers by “taking apart” a number.
We then wrote out the addition and subtraction sentences using boxes with the composed and decomposed numbers. It is interesting to see the light bulb go off as your child realizes that a number can be built in many ways, but if you take away a specific amount of gems (or subtract), there is only one number that can “fit” in that corner of the triangle. Likewise, if you subtract either number from a composed triangle statement, you will always get the other corner’s number (assuming the math has been done correctly).
You can extend this activity out more by filling in just one corner of the triangle. Draw a page full of triangles. Ask your child to put together, or compose, that number in as many different ways as they can.
Work on decomposing a number by filling in just one corner of a triangle. Draw a page full of triangles. Ask your child to take apart, or decompose, that number in as many different ways as they can.
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This post is part of the 31 Days of Homeschool Tips series.
See all of our math posts here.
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and pasta. You can use any shape or type of pasta. Add the dried pasta and a few drops of food coloring to a plastic baggie. Add a squirt of
and shake the bag. Allow the pasta to dry overnight until the dye is dry. You are ready to play. We drew a board quickly and have been playing a lot of tic tack toe. Have fun with your tic tac toe manipulatives!
, by Peter H. Reynolds, we loved the feeling of being encouraged to TRY and to use our imagination. When Ramon creates “-ish” drawings, we loved his fun ideas! We decided to use something that we play with almost every day to create and imagine just like Ramon did. We pulled out our 
and started building “block-ish” sculptures!
and a few other dried items to fit right into the caps. I had Big Sister count out the chickpeas into piles of 10. We popped them right into the caps.
and she counted out groups of tens of those, too.
and we added these lids, too.
and pretended to feed the animals.
using a 
. Peel the backing from the label sheets and stick the circles onto the bottle caps.
with lid. You’ll need your bin to be clear or see through. The size doesn’t matter, as long as it’s comparable to your light source. We used our handy 
