Addition Within 20

Grade 1 · mathematics · 264 practice problems · read aloud

🔊 Listen to this explanation

Let's Add Within 20! 🧮

What is Addition?

Addition is putting numbers together to find a total. We use it all the time, like when we count our toys or share snacks with friends!

How to Add: Step-by-Step

  1. Read the problem: Look at the two numbers you need to add.
  2. Start with the bigger number: Say the bigger number in your head.
  3. Count on: Use your fingers to count up the smaller number.
  4. Find the total: The number you land on is your answer!

Let's See Some Examples

Example 1: 8 + 4

1. Start with the bigger number: 8
2. Count on 4 more: 9, 10, 11, 12
3. The total is 12! ✅

Example 2: 5 + 7

1. Start with the bigger number: 7
2. Count on 5 more: 8, 9, 10, 11, 12
3. The total is 12! ✅

Watch Out! Common Mistakes

Mixing up numbers: Always start with the bigger number to make counting easier.

Counting the first number: If you start at 8, don't count "8" as your first finger. The next number is 9!

Super Cool Tips & Tricks

Doubles are easy! 5+5=10, 6+6=12. Try to memorize them!

Make a 10: For 9+4, think 9+1=10, then add the leftover 3 to get 13.

Use your fingers! They are your best math tools. 👍

Time to Practice!

  • Use flashcards with your family.
  • Play online math games.
  • Solve problems with small toys or cereal pieces.
  • Try these: 6+6, 9+3, 7+5, 8+8

You're going to be an addition expert in no time! 🎉

Practice problems

6 of the 264, worked through step by step — try them before opening the answer.

1 0 + 0 = ?

Hint: Think about 0 + 0

Show the answer

Answer: 0

  1. Identify the numbers to be added. We have the first number: 0. We have the second number: 0.
  2. Understand the meaning of adding zero. Adding zero to any number does not change its value. For example, 5 + 0 = 5, 2 + 0 = 2, etc.
  3. Apply this rule to our problem. Here, the first number is 0, and we are adding 0 to it. So, 0 + 0 means we start at 0 and add nothing.
  4. Perform the addition. 0 + 0 = 0.
  5. Conclusion. The sum of zero and zero is zero. Final Answer: 0

2 0 + 1 = ?

Hint: Think about 0 + 1

Show the answer

Answer: 1

  1. Identify the numbers in the problem We have two numbers: 0 and 1
  2. Understand the operation The plus sign (+) tells us we need to perform addition
  3. Recall the addition property of zero Adding zero to any number does not change that number's value. This is called the additive identity property.
  4. Apply this property When we add 0 to 1, the result is simply 1
  5. Write the calculation 0 + 1 = 1
  6. Verify the answer We can think of this as starting at 1 and adding nothing (0), so we remain at 1. Therefore,

Step-by-step solution: the correct answer is 1.

3 0 + 2 = ?

Hint: Think about 0 + 2

Show the answer

Answer: 2

  1. Identify the numbers in the problem. We have 0 and 2.
  2. Understand the operation. The plus sign (+) means we are performing addition. Addition means combining two quantities.
  3. Apply the property of zero. In mathematics, zero is known as the additive identity. This means that when you add zero to any number, the number remains unchanged.
  4. Perform the calculation. Adding 0 to 2 gives us: 0 + 2 = 2
  5. State the final answer. Therefore,

Step-by-step solution: the correct answer is 2.

4 0 + 3 = ?

Hint: Think about 0 + 3

Show the answer

Answer: 3

  1. Identify the operation We are given: 0 + 3 = ? This is an addition problem.
  2. Understand the property of zero In mathematics, zero is known as the "additive identity." This means that when you add zero to any number, the result is that same number.
  3. Apply the addition Starting with 0, we add 3: 0 + 3 = 3
  4. Verify the result If we have zero items and we add three more items, we end up with three items total.
  5. Final answer Therefore, 0 + 3 = 3

Step-by-step solution:

5 0 + 4 = ?

Hint: Think about 0 + 4

Show the answer

Answer: 4

  1. Identify the numbers in the problem. We are adding 0 and 4.
  2. Recall the property of zero in addition. Adding zero to any number does not change the value of that number. This is called the Identity Property of Addition.
  3. Apply the property to the problem. Since we are adding 0 to 4, the sum is simply 4.
  4. Write the final answer. 0 + 4 = 4

6 0 + 5 = ?

Hint: Think about 0 + 5

Show the answer

Answer: 5

  1. Identify the numbers in the problem. We are adding 0 and 5.
  2. Recall the property of zero in addition. Adding zero to any number does not change the value of that number. This is called the Additive Identity Property.
  3. Perform the addition. Start with the number 5. Since we are adding 0, we count zero units away from 5. This means the quantity remains the same. Therefore, 0 + 5 = 5.
  4. State the final answer. The sum of 0 and 5 is 5.
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