Grade 1 Subtraction Within 20 Worksheet

This worksheet gives young learners a gentle introduction to subtraction. Children will practice taking away numbers within 20 while building strong number sense. Each problem helps students understand how numbers get smaller when we subtract.

What Students Will Learn

• How to subtract numbers within 20 step by step
• Understanding subtraction as “taking away”
• How to count backward correctly
• Building confidence in solving simple math problems

How to Solve (Step-by-Step)

Example Problem:

13 - 1 = ?

Step 1: Look at the first number. This is the number you start with. Here, we start with 13.

Step 2: Look at the number you need to subtract. This tells you how many steps to move backward. We subtract 1, so we move back 1 step.

Step 3: Count backward slowly. Start at 13 and go back one number: 12.

Step 4: Stop after moving the correct number of steps. Since we moved back 1 step, we stop at 12.

Step 5: Write your answer. 13 - 1 = 12.

Another Example:

17 - 15 = ?

Step 1: Start with 17.

Step 2: We need to subtract 15, so we will count backward 15 steps.

Step 3: Count carefully: 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2.

Step 4: After counting back 15 steps, we land on 2.

Step 5: The answer is 2.

This method helps students clearly see what subtraction means. Moving backward step by step makes it easier to avoid mistakes and understand how numbers change.

Worksheet Details

• Total Questions: 25
• Difficulty: Easy (Beginner Level)
• Number Range: 1 to 20
• Format: Vertical subtraction problems

Who Is This For?

This worksheet is perfect for Grade 1 students who are learning subtraction for the first time. It is also useful for parents and teachers who want structured and easy practice material.

Practice Tips

• Use number lines to help visualize counting backward
• Practice slowly and carefully rather than rushing
• Encourage children to say numbers out loud
• Repeat similar problems to build confidence

FAQs

What does subtraction mean?

Subtraction means taking away. It shows how many are left after removing some items.

Why is counting backward important?

Counting backward helps students understand how subtraction works and reduces mistakes.

What if my child makes mistakes?

Mistakes are part of learning. Encourage your child to go step by step and check their counting.