This is a first blog post in a series about Counting Principles. These principles are helpful when developing children’s number sense. It’s not enough for them to learn to count by rote, they have to develop a strong foundation of numbers and counting.
Subitzing is the first principle that I am taking a deep dive into.
What is Subitzing?
It is the ability to tell the number of objects in a set without counting. There are two types of subitizing skills: perceptual subitizing involves looking at a small set of objects and knowing the number without counting (4 dots), conceptual subitizing means that you can recognize small sets within a group without counting and adding them together (three dots plus three dots makes 6 dots).
Why is Subitizing important?
Developing this skill helps develop children’s math fluency skills, and mental math abilities.
Activities to Work on Subitizing Skills
Number Talks are a great way to work on subitizing skills. There are so many different ways that you can do a number talk. I’ll explain to you my favourite way:
Students sit in front of you (I have them sit on the carpet), and I have my subitizing cards ready. I usually start the year with regular dot cards, then I move on to 5 frames, 10 frames and then completing a number set. I have students hold a fist to their chest to show me that they are ready. Then I show them the first card for a few seconds (I usually start at one end of the carpet and sweep across the carpet so that each student sees it for about 5 seconds). Once a student thinks that they know how many where on the cards, they give me a thumbs up while keeping their first on their chest (the reasoning behind this is so that it doesn’t intimidate other students- no one knows who has an answer other than the teacher, so no one gives up, and they all have a chance to think about their answer). Once most of the students have their thumbs up, I ask a student what number they saw. If other students agree with their they stick out their thumb and pinkie finger and shake their hand. Then I ask them how they saw that number and I write down their answer (2+2=4), and I ask if anyone else saw it a different way (1+3=4). This is a great way to highlight their math thinking, and talk about numbers.
I made a video tutorial explaining how I do my Number Talks in Kindergarten:
I use these packs during my Number Talks. I put each of these sets on rings so that I can do a quick Number Talk whenever I have a minute:
To practice subitizing sets of numbers, I would put these cards upside down on the table and have students turn them over and write the number without counting. You could use whiteboards, blackboards or magnetic boards. Students could also hold them up for each other an play in pairs with the cards.
If you would like to use these cards, they are a free download in my Resource Library (if you do not have he password, sign up for my newsletter and it will be sent to you):
Spin and Cover Subitizing Game
If your students need more practice with their subitizing skills, these Spin and Cover workmats are perfect for independent math centers: