Subitizing and Visualizing Math

A few weeks ago I participated in listening to problems with basic math, I am not sure on the exact topic or title, from the Global Math Department. It talked about subitizing numbers and the primary grades K-3.

I mentioned in the chat that I didn't teach K-3, but taught middle school and I knew I was teaching integers, so I threw it out there hoping someone had tried it at the older grades. Nobody volunteered with the yes here's what've used, but more along the lines that's a great idea let's try it with integers.

Well today was the day. I made a flipchart with active inspire and tried my hand at Yellow and Red Chips Subitizing with my 7th Grade Math Class. We've practiced with integer chips (Tile Spacers from Home Depot cut into - and +) . So for those who don't know subitizing is the ability to group numbers quickly to see patterns and what numbers appear.

I initially flashed the problem below

Students then were asked to show me with number cards what they thought they saw. (We practiced one with positive numbers only first).  Most answers were 1 or 2 off and sometimes the positive and negative were off. Then I gave students a chance to revise their answers by flashing this:

Showing them in a ten frame. This allowed them to see zero pairs better. Once I showed students the frames and they shared their answer we went over what the answer was with the screen still.

Students were very engaged. To not a lot of surprise the stronger students in math showed a much more accurate initial reading than those who aren't. It also increased engagement because they got one glance and if they weren't paying attention it was to late. 

I think I will make a handful to use throughout the week and keep practicing. I may expand on this and try some before's and afters where students write the problem with either subtraction or addition.