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Complete a Pattern

A kindergarten introduction to completing a pattern: spotting the repeating core in a sequence of colors, shapes, or sizes and using it to predict and fill in what comes next.

What Does It Mean to Complete a Pattern?

A pattern is a set of colors, shapes, sizes, or objects arranged in a way that repeats in a predictable order. Completing a pattern means looking at the part that has already been made, figuring out the rule it follows, and then filling in the piece that comes next. This is one of the very first ways young learners begin to notice order and make predictions in math.

Patterns can show up in many forms. Some patterns repeat colors, like in color patterns, some repeat shapes, as in shape patterns, and some repeat by getting bigger, as in growing patterns. No matter which kind it is, completing a pattern always starts the same way: find what repeats.

Finding the Core of a Pattern

Every repeating pattern has a core, which is the smallest group of items that repeats over and over. For example, in the pattern red, blue, red, blue, red, blue, the core is just two items: red, blue. Once the core is found, the pattern can be extended as far as needed by repeating that same small group again and again.

A good way to find the core is to say the pattern out loud and listen for where it starts to repeat. Clapping or tapping along with each item can also help a child hear the rhythm of the pattern before trying to complete it.

Step-by-Step: How to Complete a Pattern

Look at each item in the pattern from left to right.
Say the names of the items out loud, such as circle, square, circle, square.
Find the smallest group of items that keeps repeating. This is the core.
Use the core to decide which item should come next.
Fill in the missing piece and read the whole pattern again to check that it still makes sense.

Worked Example: An ABAB Color Pattern

Look at the row of circles below. Two colors repeat one after another, and one spot is left blank for what comes next.

The core is red, blue. After red, the next color must be blue.

Saying the pattern out loud gives: red, blue, red, blue, red, and then the missing circle. Since the core is red, blue, and the last circle shown is red, the missing circle must be blue.

Worked Example: A Shape Pattern

This pattern repeats a square and a triangle instead of colors.

The core is square, triangle. After the triangle, a square comes next.

The core here is square, triangle. The pattern shows square, triangle, square, triangle, so the missing shape after the last triangle must be another square.

Practice Tips for Completing Patterns

When practicing, it helps to point at each item while saying its name and to always start from the very beginning of the row rather than jumping straight to the blank space. Covering the answer with a finger and reading the pattern again afterward is a simple way to check that the completed pattern makes sense. Once completing a pattern feels comfortable, the same core-finding skill can be used to compare patterns of different sizes, as in size patterns, or patterns that grow step by step.

Related lessons

Kindergarten