# Subitizing

Subitizing is the ability to ‘see’ a small amount of objects and know how many there are without counting. Subitizing is what tells you what number you roll on a six sided dice – most adults no longer have to count the pips after playing board games for a while.

Subitizing is a fundamental skill in the development of students’ understanding of number (Baroody 1987, 115). Students use patterns recognized to discover properties and skills such as conservation, compensation, unitizing, counting on, composing and decomposing numbers, as well as understanding of arithmetic and place value.space

 The ability to subitize can be developed, and uses a student’s pattern recognition skills. Part part whole understanding is usually used to subitize numbers over four or five. This means a student looking at this pattern doesn’t usually see 7, but instead 1 and 6, or maybe 2 and 5. This is one of the reasons larger patterns shouldn’t be used until students are familiar with various representations of numbers 1 to 5. When two colours are used in patterns, they also draw attention to smaller anchors and make the parts more obvious. Subitizing pattern for 7

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 Dot PlatesA common tool is a set of dot patterns on paper plates – the dots can be easily made with a bingo dabber.  Since paper plates are round, they are held up in essentially a random orientation each time.  Two colours are used for advanced plates. Click the picture on the right for a pdf of suggested patterns from Elementary and Middle School Mathematics: Teaching Developmentally. Dot Plate Questions / Activities Dot plates are very effective when used for a few minutes of mental / oral math each day.  This file details questions and tools for using dot plates as part of your program. Dot Cards A set of dot cards useful for a variety of student activities.  This set contains 4 representations of the numbers 1 to 10, some with ten frames. Dot Card Activities A set of six basic games and activities (War, Trains, Number Sandwiches, Go Fish, Ten and Out) for the dot cards above. Concentration Cards Beginner This is a set of cards from Manitoba Education and Youth.  It includes four different representations of the numbers 1 to 6, and is suitable for playing concentration or other games in Kindergarten or grade 1. Concentration Cards Advanced This is a set of cards from Manitoba Education and Youth. It includes four different representations of the numbers 5 to 10, and is suitable for playing concentration or other games in grade 1 to 3. Domino Activities Dominoes can help develop the ability to recognize dot patterns. This is a set of games and activities that use dominoes. Double 9 dominoes are a little more versatile when students are ready. Domino Flash Cards These are large domino cards that can be used for subitizing. for numbers over 6, dominos have smaller anchors built into them due to the two halves. For this reason, these are valuable addition to subitizing activities.