Number sense is the ability to understand the quantity of a set and the name associated with that quantity. Strong number sense developed in the early years is a key building block of learning arithmetic in the primary grades, as it connects counting to quantities, solidifies and refines the understanding of more and less, and helps children estimate quantities and measurements. © Erikson Institute’s Early Math Collaborative. Reprinted from Big Ideas of Early Mathematics: What Teachers of Young Children Need to Know (2014), Pearson Education.

Number sense involves some Big Ideas that can be explored with children, such as:

May 19, 2021

What is cardinality? And how is it related to counting? The common definition of cardinality states that it’s the understanding that the last number word said when counting tells how many in all.

- Topic: Counting, Number Sense, Sets
- Age/Grade Level: Kindergarten, Pre-K
- Tags Cardinality

To encourage teachers and other adults to use rekenreks, it's important to not only go over ways to use a rekenrek, but also we thought we would make sure everyone has opportunities to have them, whatever the budget.

- Topic: Counting, Number Sense
- Age/Grade Level: Kindergarten, Pre-K
- Tags Rekenrek, Subitizing

Looking for new rekenrek activity ideas? Try voting with a rekenrek chart. In this video, we see a rekenrek chart used to solve a dilemma common to early childhood classrooms: choosing between two favorite books at story time.

- Topic: Data Analysis, Number Sense
- Age/Grade Level: 1st Grade, Kindergarten, Pre-K
- Tags Rekenrek, Subitizing

A good sense of the number ten is critical for building young children’s reasoning strategies. Here we see kindergarteners making the number ten on a rekenrek, a tool with red and white beads in groups of 5s with 10 beads on each row.

- Topic: Number Sense
- Age/Grade Level: 1st Grade, Kindergarten
- Tags Rekenrek, Subitizing

As children start using number words, they don’t always have a sense of what those words really mean. Early on, we guide children to develop a meaningful number sense by focusing on small numbers.

- Topic: Number Sense
- Age/Grade Level: Kindergarten, Pre-K
- Tags Family Math, More Fewer Less, Pat Mora, Sergio Ruzzier, Subitizing, Tana Hoban, Two Mice, Uno Dos Tres/One Two Three

En Español También. Do you remember enjoying fingerplay songs like 5 Little Monkeys or Un Elefante Se Balanceaba when you were young? You may not have realized that sharing these songs is a great way to bring math to life.

- Topic: Counting, Number Sense
- Age/Grade Level: Kindergarten, Pre-K
- Tags En Español, Family Math, Games, Gesture

En Español También. Path games are fantastic ways for families to spend time together and have fun while doing math. Path games develop number sense, counting skills and, depending on children’s ages and the tools you use, computational fluency.

- Topic: Counting, Number Sense
- Age/Grade Level: 1st Grade, Kindergarten, Pre-K
- Tags En Español, Family Math, Games

En Español También. Going for walks is an excellent time to talk about math with your child. You’ll be surprised how much math talk you can have when you look for the math in your very own neighborhood.

- Topic: Counting, Number Sense, Shape, Spatial Relationships
- Age/Grade Level: 1st Grade, 2nd Grade, 3rd Grade, Kindergarten, Pre-K
- Tags En Español, Family Math

Children love to count. Counting helps them make sense of the world and to find out how many of something. With time and practice, children develop an understanding of the “rules” or principles of counting.

- Topic: Counting, Number Sense
- Age/Grade Level: Kindergarten, Pre-K

There are all kinds of things to count in pre-k to second grade classrooms. Counting Collections is an activity that develops the Big Ideas of number sense and counting, such as cardinality, one-to-one correspondence, and unitizing.

- Topic: Counting, Number Sense
- Age/Grade Level: 1st Grade, 2nd Grade, Kindergarten, Pre-K
- Tags Cardinality