Addition and subtraction

Basic addition and subtraction

Learn

Basic addition
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Basic subtraction
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Practice

Add within 5Get 5 of 7 questions to level up!
Subtract within 5Get 5 of 7 questions to level up!

Addition and subtraction within 20

Learn

Adding 8 + 7
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Subtracting 14 - 6
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Practice

Add within 20Get 5 of 7 questions to level up!
Subtract within 20Get 5 of 7 questions to level up!

Strategies for adding and subtracting within 100

Learn

Adding 53+17 by making a group of 10
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Adding by making a group of 10
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Strategies for adding 2-digit numbers
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Addition and subtraction with number lines
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Practice

Add 2-digit numbers by making tensGet 3 of 4 questions to level up!
Add 2-digit numbers by making tens 2Get 3 of 4 questions to level up!
Select strategies for adding within 100Get 5 of 7 questions to level up!
Add and subtract using a number lineGet 3 of 4 questions to level up!

Addition within 100

Learn

Adding 2-digit numbers without regrouping 2
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Adding with regrouping
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Practice

Add within 100Get 5 of 7 questions to level up!

Subtraction within 100

Learn

Subtracting 2-digit numbers without regrouping 1
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Subtracting with regrouping (borrowing)
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Practice

Subtract within 100Get 5 of 7 questions to level up!

Word problems within 100

Learn

Subtraction word problem: tennis balls
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Addition word problem: horses
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Subtraction word problem: snow
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Subtraction word problem: crayons
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Practice

Add and subtract within 100 word problems 1Get 5 of 7 questions to level up!
Add and subtract within 100 word problems 2Get 5 of 7 questions to level up!

Multi-digit addition with regrouping

Learn

Using place value to add 3-digit numbers: part 2
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Adding 3-digit numbers
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Relate place value to standard algorithm for multi-digit addition
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Adding multi-digit numbers: 48,029+233,930
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Practice

Add within 1000Get 3 of 4 questions to level up!
Multi-digit additionGet 3 of 4 questions to level up!

Multi-digit subtraction with regrouping

Learn

Worked example: Subtracting 3-digit numbers (regrouping)
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Worked example: Subtracting 3-digit numbers (regrouping twice)
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Worked example: Subtracting 3-digit numbers (regrouping from 0)
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Subtracting in your head (no regrouping)
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Relate place value to standard algorithm for multi-digit subtraction
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Multi-digit subtraction: 389,002-76,151
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Practice

Subtract within 1000Get 3 of 4 questions to level up!
Multi-digit subtractionGet 3 of 4 questions to level up!

About this unit

In this topic, we will add and subtract whole numbers. The topic starts with 1+1=2 and goes through adding and subtracting within 1000. We will cover regrouping, borrowing, and word problems.