# subtraction – am I the last one? {printable}

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Two weeks ago, I was fussily taking some photos from our math journals to share and it hit me.

I was teaching my kinders wrong!

Okay, not wrong, but I could be teaching them better! Why, when I am working with them in groups or during our whole group calendar time, am I modeling subtraction by doing this?

Why am I modeling crossing out individual items for subtraction? It was bugging me the other day when some of my kinders who ‘take longer to catch onto some math concepts’ were modeling subtraction in their notebooks using one single x to cross out the entire lot. It bugged the part of me that likes things neat and organized because it was harder to see exactly how many had been crossed off and  for them to check their work essentially, because the sides of the x are rather open, making it visually more difficult.

I am so thankful that I realized they were seeing taking away an entire group of objects (which is higher level thinking than I was giving them credit for) and they were also able to “see” (without counting 1:1) the set to cross it out! We are talking about “seeing” groups of two and three objects, but I was reminded of how huge that really is!

So, now comes the application… Because really, what good is it if I don’t apply what I’ve learned? I started immediately modeling subtraction (with a ten frame for example) by crossing items out like this instead. My kinders were tickled at how fast this was and loved it.

It may be a small tweak, but to me, its a meaningful one! Am I the last one out there to do this?

To help with building our subtraction skills, I recommend making copies of these subtraction cards onto colored construction paper for keeping track of multiple sets easily (when working with groups) and for increased durability if you laminate them. I use these in small groups to practice modeling the equations with ten frames, number lines and touch dots until they begin to become very familiar with them.

Ha! Well, let me put it into application for my kinders to see visually while playing games in our independent practice math zone. I created this set after reflecting on this new realization. It helps develop focus on what’s left, what’s taken away and visualizing subtraction scenarios.

These should help build some mental images for my kinders who are still working on that (and that’d be most of them!)

Now… be honest. Am I really the last one to have figured this out? If you like what I do here on KindergartenWorks, then be sure to subscribe today. I look forward to sharing ideas with you weekly.

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