• You can count on to find 9 + 8.
• Start at 9 and count on 8 times.

• You end at 17.
• 9 + 8 = 17

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• You can also add using doubles minus one.
• Remember the doubles fact 9 + 9 = 18.
• Notice that 9 + 8 is 1 less. That makes 17.
• 9 + 8 = 17

When you add 0 to a number, the number stays the same.

9 + 0 = 9

• You can count on to find 9 + 10.
• It is easier to start with the larger number. So, start at 10. Count on 9 times.

• You end at 19.
• 9 + 10 = 19

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• You can also think about place value to add.
• 9 + 10 is 1 ten and 9 ones.

• That makes 19.
• 9 + 10 = 19