K.MD.3: Classifying Objects

I can sort objects into categories and count how many are in each category.

What Your Child Needs to Know

This standard focuses on helping your child classify objects into categories and count the number of objects in each category. Children learn to sort objects based on attributes like color, shape, size, or function, and then count how many objects are in each group.

Classifying and counting objects helps children develop important mathematical skills like comparing quantities, recognizing attributes, and organizing information. These skills are foundational for data analysis and problem-solving in later grades.

Real World Practice

Visual models and hands-on activities

Visual Models

1. Sorting Mats

Create simple mats or hoops to define different categories. Children place objects in the appropriate category area.

2. Sorting Diagrams

Draw circles or boxes on paper to represent different categories. Label each with a picture or word.

3. Attribute Blocks

Use blocks or objects that vary in color, shape, and size. Sort them based on different attributes.

4. Picture Sorts

Use pictures of objects that can be sorted into categories (e.g., animals, food, clothing).

Everyday Activities

1. Laundry Sort

Have your child help sort laundry by color, type (shirts, socks, pants), or family member. Count the items in each pile.

2. Grocery Sort

After shopping, sort groceries by type (fruits, vegetables, dairy) before putting them away. Count items in each category.

3. Toy Clean-Up

When cleaning up toys, sort them into appropriate bins or shelves. Count how many toys go in each place.

4. Nature Collection

Collect items from nature (leaves, rocks, sticks) and sort them by type, color, or size. Count each group.

5. Sock Match

Sort socks by color, size, or pattern. Count how many pairs of each type you have.

Quick Checks

Strategies and quick activities

Strategies When Your Child Struggles

1. Start Simple

Begin with sorting by one obvious attribute (like color) before moving to more complex sorts.

2. Be Explicit

Clearly state the sorting rule: "We're sorting by color. Red ones go here, blue ones go here."

3. Ask Questions

Ask your child questions about their sorting: "Why did you put this one here?" This helps them articulate their thinking.

4. Model Counting

After sorting, model how to count the objects in each category. "Let's count how many red ones we have: 1, 2, 3..."

5. Compare Groups

Ask questions about the sorted groups: "Which group has more? Which has fewer? How do you know?"

5-Minute Practice Activities

Activity 1: Button Sort

Collect buttons of different colors, sizes, and number of holes. Sort them by one attribute, then count each group.

Activity 2: Food Sort

Use small snacks like fruit pieces, crackers, or cereal. Sort by type or color, then count each group.

Activity 3: Toy Sort

Gather small toys and sort them by category (animals, vehicles, people), then count each group.

Activity 4: Shape Sort

Cut out different shapes from colored paper. Sort by shape or color, then count each group.

Check Progress

Track improvement

By the middle of the year, your child should:

  • Sort objects by one obvious attribute (like color or size)
  • Count the number of objects in each category (up to 10)
  • Begin to compare quantities in different categories

By the end of the year, your child should:

  • Sort objects by various attributes (color, shape, size, function)
  • Count objects in categories (up to 10 or more)
  • Compare quantities in different categories using appropriate language (more than, less than, equal to)
  • Explain their sorting rule or category criteria

Simple Assessment:

Give your child a collection of objects that can be sorted in multiple ways. Ask them to sort the objects and explain their sorting rule.
After sorting, ask your child to count how many objects are in each category.
Ask comparison questions: "Which category has the most? Which has the least? How many more are in this group than that group?"

Differentiation

Support for all learning levels

Below Grade Level

If your child is struggling with sorting and counting, these resources focus on building foundational skills with simpler sorting activities and more visual supports.

📥 Download Practice Worksheet

At Grade Level

These resources provide practice at the kindergarten level, focusing on sorting objects into categories and counting the objects in each category.

📥 Download Grade Level Worksheet

Above Grade Level

If your child has mastered basic sorting and counting, these resources extend their learning with more challenging sorting activities and data analysis.

📥 Download Challenge Worksheet