Adding whole tens (3 addends, missing)
Browse 0 free printable Adding whole tens (3 addends, missing) worksheets for Third Math. These Addition worksheets are designed to give students targeted practice and build confidence in math.
Worksheets are available at multiple difficulty levels — Easy, Medium, and Hard — so you can meet every student where they are. Each worksheet is an instant PDF download: print as many copies as you need for your classroom, tutoring sessions, or home practice at no cost.
Whether you're a teacher looking for addition practice problems, a homeschool parent building a Third curriculum, or a tutor helping a student catch up, these free printable worksheets are ready to use today.
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What to Do Next
Practice Questions
- 30 + ? + 10 = 120
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80
- 40 + ? + 20 = 100
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40
- 50 + ? + 30 = 110
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30
- 20 + ? + 40 = 100
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40
- 70 + ? + 10 = 120
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40
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Teacher Resources
Teaching Notes
This challenges students to work backwards. Strategy: Add the two known numbers first, then subtract from the total. Example: "I know 30 + 40 = 70, and I need 100, so the missing number is 100 - 70 = 30." Encourage students to check their answer by adding all three numbers.
Vocabulary
Common Mistakes
- Subtracting in wrong order
- Adding the two known numbers and stopping
- Forgetting to check the answer
- Confusing which number is missing
- Forgetting to add the two known addends together before subtracting from the sum.
- Errors in basic addition or subtraction of whole tens.
- Misunderstanding the concept of a missing addend.
Differentiation
Discussion Questions
- What strategies can you use to add whole tens quickly?
- How does knowing about subtraction help you find the missing number in an addition problem?
- Can you explain your strategy for finding the missing whole ten to a partner?
Extension Activities
- Use a number line to find differences.
- Create equations with missing addends.
- Play 'find the missing piece'.
Parent Tip
Give your child a total and two numbers; ask them to find the missing number.
Learning Path
Skill Cluster
Number Sense & Algebraic Thinking
Estimated Time
15 minutes