Below you will find videos to help you understand the subitzing levels described in Subitising through the years (Faulkner, Ainslie, 2017). Use these videos to learn how to subitize like a pro!

The videos are organized by levels. Begin at Perceptual Subitizing 1 (P1). Review the article, the content connections, the learning trajectory connections and watch the practice and troubleshooting videos for each level. You will then be prepared for your students. With your students, stay within a level until you have 100% speed and mastery with 95%-100% of students. Once you progress to a new level with the class, you will want to include some slides from earlier levels to keep up the Speed.

Subitizing is a speedy activity for a reason. To subitize is to see a value suddenly without underlying mathematical computation (such as adding). You just see it!! This can be done with quantities/sets up to 5. After that, the brain clumps together numbers in order to quantify the value of the set, in order to know the value of the set. We can often Subitize to understand the cardinal number of a set (the total quantity in the group) WITHOUT the need to count. This is a mathematical revelation. For more on this see Subitising through the years, Faulkner, Ainslie, 2017. Subitizing: What is it? Clements, 1999; and the book The Number Sense, Stanislas Dehaene first issued in 1999.

Each level has a powerpoint presentation for you to use, and build from, in your own classroom. For the first few levels there are a couple of sets so that you can get used to how to vary your lessons within a subitizing session. Each set has a practice video where I talk and run through the set as if children were present and I also discuss the instructional issues directly. These practice sets are critical to ensure you understand the purpose of a given level. Also critical are the Troubleshooting videos that anticipate key considerations that often come up. Content connections are noted throughout. Also see Subitising through the years, Faulkner, Ainslie, 2017. In the early levels I have a Live Action video as well that you can use directly with children until you get used to the timing.

Presentations slides and videos below. You can also click here for more subitizing powerpoint slides you can use to generate your classroom presentations.

**PERCEPTUAL LEVEL 1 (0-3, Metacognition: Subitizing!!, Conservation of Number)**

P1 Set 1 (0-3) Practice

P1 Set 1 (0-3) “Live Action”

P1 Set 2 (0-3) Practice

P1 Set 2 (0-3) “Live Action”

Troubleshoot P1

**PERCEPTUAL LEVEL 2 (0-5, Metacognition: Subitizing!!, Conservation of Number)**

P2 Set 1 (0-5) Practice

P2 Set 1 (0-5) “Live Action”

P2 Set 2 (0-5) Practice

P2 Set 2 (0-5) “Live Action”

Troubleshoot P2

**CONCEPTUAL LEVEL 1 (0-5, Composing small **s**ets to process the value of the larger set)**

C1 (0-5) Practice

C1 (0-5) “Live Action”

Troubleshoot C1

**CONCEPTUAL LEVEL 2 (0-9, Composing small sets to process the value of the larger set)**

C2 (0-9) Practice

C2 (0-9) “Live Action”

Troubleshoot C2

**CONCEPTUAL LEVEL 3 Missing Addends, Subtrahends, Minuen****ds** 0-9

C3 (0-5) Practice

Troubleshoot C3

**CONCEPTUAL LEVEL 4 Seeing Differences/Match Compare**

C4 Practice

Troubleshoot C4

C5 will be posted sometime this winter. Wanted to get to C6 and C7!