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Unit 1: Addition, subtraction, and estimation
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About this unit
Learn how to estimate, add, and subtract with three-digit numbers by thinking about ones, tens, and hundreds.
Learn
Practice
- Round to nearest 10 or 100 on the number lineGet 5 of 7 questions to level up!
- Round to nearest 10 or 100Get 3 of 4 questions to level up!
- Round to nearest 10 or 100 challengeGet 3 of 4 questions to level up!
Learn
Practice
- Break apart 3-digit addition problemsGet 3 of 4 questions to level up!
- Add using groups of 10 and 100Get 3 of 4 questions to level up!
- Add on a number lineGet 3 of 4 questions to level up!
- Estimate to add multi-digit whole numbersGet 3 of 4 questions to level up!
Learn
Practice
- Subtract within 1000Get 3 of 4 questions to level up!
Practice
- Find the missing number (add and subtract within 1000)Get 3 of 4 questions to level up!
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Level up on all the skills in this unit and collect up to 1,000 Mastery points!