Make a number using subtraction – numbers up to 20

key notes :

Understanding Subtraction:

Subtraction is the process of taking away one number from another. It is the opposite of addition.

Using Objects for Subtraction:

Use physical objects (like counters, blocks, or drawing objects) to visually represent subtraction. For example, start with 10 objects and remove 3 to show the subtraction of 3 from 10.

Simple Subtraction within 20:

Focus on simple subtraction problems like:

  • 10 – 4 = 6
  • 15 – 7 = 8
  • 20 – 5 = 15

Number Line:

Teach students to use a number line for subtraction. They can count backward from the starting number to find the answer. For example, from 10, count back 4 steps to land on 6.

Subtraction Vocabulary:

Introduce terms like “take away,” “minus,” “less,” and “remaining.” These help students understand the concept more clearly.

Story Problems:

Create simple word problems using subtraction:

  • “You have 12 apples, and you give away 4. How many apples do you have left?”

Learn with an example

🥦How do you make 9?

  • 10 − 2
  • 10 − 1
  • 8 − 1
  • 9 − 1

This is a way to make 9:

  • 10 − 1 = 9

These are not ways to make 9:

  • 10 − 2 = 8
  • 8 − 1 = 7
  • 9 − 1 = 8

🥦How do you make 4?

  • 6 − 2
  • 7 − 5
  • 10 − 4
  • 10 − 5

This is a way to make 4:

  • 6 − 2 = 4

These are not ways to make 4:

  • 7 − 5 = 2
  • 10 − 4 = 6
  • 10 − 5 = 5

🥦How do you make 7?

  • 8 − 2
  • 10 − 3
  • 9 − 3
  • 9 − 1

This is a way to make 7:

  • 10 − 3 = 7

These are not ways to make 7:

  • 8 − 2 = 6
  • 9 − 3 = 6
  • 9 − 1 = 8

Let’s practice!