An addition fact family connects two addends and their sum through related equations: the two orders of addition and the two corresponding subtraction facts, such as 6 + 4 = 10, 4 + 6 = 10, 10 − 6 = 4, and 10 − 4 = 6. This establishes addition and subtraction as inverse operations and links part–part–whole relationships, limited to whole-number facts with sums through 20 rather than larger numbers or generalized algebraic fact families.
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Detailed Explanation: Use addition fact families
A fact family uses the same three numbers to make two addition facts and two subtraction facts.
Use the numbers , , and .
- The two smaller numbers are the parts: and . The largest number is the whole: .
- Add the parts in both orders:
- Start with the whole, , and subtract one part at a time:
So, the fact family is:
The addition facts put the parts together. The subtraction facts take one part away from the whole.
Learn by doing: Use addition fact families
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Practice:
Fact Family - Addition - Triangle to Fact
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Download/Modify Free Grade 1 'Use addition fact families' Worksheet
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This Worksheet Includes:
- Fact Family - Addition - Triangle to Fact
- Fact Family - Addition - Fact to Triangle
- Picture Numbers - Adding - Picture to Equation (Within 20)
- Addition - Whole Number - Within 5 - Column
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