Developing Number Sense: Principles of Counting
All concepts of number sense need to be actively taught.
The one-to-one correspondence principle ensures we accurately count objects one at a time.
One-to-One Correspondence Principle
When children first learn to count a set of objects they often will randomly touch the objects in any order and will count the same object more than once or even multiple times.
When students understand the concept of one-to-one correspondence, they understand that each object is counted only once and that each object represents one number.
Touch counting helps students develop this skill and it usually has to be modelled for students to learn how to do it properly.
We can either simply touch an item or move it away from the group being counted in order to ensure that we have counted all of the objects in the set. Moving objects away is a skill for children to learn at the beginning of understanding this concept. When a child has a stronger working memory they do not need to rely on this skill.