Unit 3: Number Sense and Place Value

Day 2 of 30

Count objects from 11 to 20

K-2Mathematics

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Learning Objective

I can count objects from 11 to 20.

Today's Lesson

Today we will learn how to count objects from 11 to 20. Math helps us solve problems and understand the world around us.

Counting is the foundation of all mathematics. When counting objects, point to each one and say the next number—this one-to-one correspondence means every object gets exactly one number. Numbers 1–10: one, two, three, four, five, six, seven, eight, nine, ten. Numbers 11–20 follow a pattern: eleven (11), twelve (12), thirteen (13), fourteen (14)… twenty (20). Important principles: (1) The last number you say tells how many (cardinality); (2) Objects can be counted in any order—the total stays the same (order irrelevance); (3) Each object is counted once. Practice by counting real objects around you, lining them up, then counting again in a different order.

Let's break this down step by step so it's easy to understand. Follow along with the examples, and don't worry if it takes some practice to get the hang of it!

Remember: Making mistakes is part of learning. If something is tricky, try again, look at the examples, or ask for help.

Key Terms
Problem

A question we need to solve

Solution

The answer to a problem

Activities
Instructions
1. Use objects or pictures to explore count objects from 11 to 20. 2. Try the examples together. 3. Solve practice problems. 4. Check your work.
Materials Needed
  • Counters or objects
  • Pencil
  • Practice sheet
Practice Problems
1

Practice Problem 1: Apply what you learned today.

Hint: Review the examples from the lesson.
2

Practice Problem 2: Try a similar problem on your own.

Hint: Use the strategies you learned.
3

Challenge: Can you create your own problem like the ones we practiced?

Hint: Think about the pattern in the problems.

Teaching Tip

For younger learners: Use concrete objects and hands-on activities when teaching count objects from 11 to 20. Keep sessions short (10-15 minutes) and incorporate movement or songs when possible.

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