1.3 Adding and Subtracting Within 20

Unit Goals

• Students add and subtract within 20. Students apply the properties of operations and the relationship between addition and subtraction.

Section A Goals

• Build toward fluency with adding and subtracting within 10.

Section B Goals

• Add and subtract one-digit numbers from teen numbers without composing or decomposing a ten.
• Find the value that makes an addition or subtraction equation true, involving 10.
• Understand 10 ones as a ten and the numbers 11 to 19 as a ten and some ones.

Section C Goals

• Add within 20, including three addends.

Section D Goals

• Subtract within 20.

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