Common Core Math · Kindergarten

K.MD.B.3 Classify objects into categories and count each group

Classify objects into given categories; count the numbers of objects in each category and sort the categories by count.

Why water teaches this standard well

Students sort picture cards of animals into 'lives in water' and 'lives on land' piles, then count each pile and say which has more. Sorting water-use pictures into 'inside the house' and 'outside the house' extends the same skill to a topic students will revisit in every later grade.

Materials tagged with this code are written to the full standard , and each carries a written note explaining the alignment. See how we review materials.

20 materials aligned to K.MD.B.3

Lesson plans

Kindergarten Lesson plan

Cold Tap, Warm Tap: A Kindergarten Sink Safety Lesson

A 30-minute kindergarten lesson on sink safety: naming the cold and warm taps, testing water with the back of one hand, and sorting eight sink jobs.

Health & Consumer Science 30 min Answer key

Kindergarten Lesson plan

Why the Town of Tin Cup Grew Beside the Creek

A 35-minute kindergarten lesson where children sort near-water and far-from-water places on a map page, count each group, and tell why towns grow by creeks.

Social Studies & Civics 35 min Answer key

Worksheets

Kindergarten Worksheet

The Water Crew's Gear Bag at Wildrose School

A kindergarten careers worksheet where students pack a water crew's gear bag by sorting seven read-aloud items, then count the gear and draw one piece.

Careers & CTE 20 min Answer key

Kindergarten Worksheet

A Mud Fence for the Fiddlehead Creek Building Site

A read-aloud kindergarten worksheet where students sort five fence materials into ones that stop mud and ones that let it pass, then draw a fence beside a creek.

Engineering & Design 20 min Answer key

Classroom activities

Kindergarten Classroom activity

Every Shop on Cobbler Street Needs Water

A 30-minute kindergarten matching activity where partners pair ten shops on a made-up street with the water job each one depends on, then build a class paper street.

Social Studies & Civics 30 min Answer key

Kindergarten Classroom activity

The Raindrop Path Necklace: A Water Cycle Bead Craft

A kindergarten art activity where students string a four-color bead necklace that sequences the stages of the water cycle, counting and sorting beads by color.

Art & Music 30 min Answer key

Graphic organizers

Kindergarten Graphic organizer

Three Kinds of Water: A Kindergarten Sorting Organizer

A three-column kindergarten organizer sorting twelve everyday water pictures into water we drink, water we wash with, and water we stay out of, with a filled exemplar.

Health & Consumer Science 20 min Answer key