Skill: Find a missing addend

Explanation and Free Practice Resources

Finding a missing addend means determining the unknown part in an addition equation, such as $247+\square=563$ , by interpreting the total as the sum of two parts and using subtraction as the inverse of addition: $563-247=316$ . The reasoning applies to whole numbers within 1,000, including equations represented with place-value models, number lines, or bar models, and establishes fact-family relationships that support later work with multi-digit computation and algebraic equations; fractions, decimals, and more general unknown-value equations are not included.

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Detailed Explanation: Find a missing addend

When an addition equation has a missing addend, subtract the known addend from the total.

In the equation

247+\square=563

$563$ is the total.
$247$ is one addend.
$\square$ is the missing addend.

Use subtraction to find the missing part:

563-247

Subtract by place value:

Ones: $3-7$ cannot be done, so regroup. $13-7=6$ .
Tens: After regrouping, $5$ tens becomes $4$ tens. Regroup again: $14-4=10$ .
Hundreds: $4-2=2$ .

So,

563-247=316

The missing addend is $\boxed{316}$ .

Check by adding:

247+316=563

Therefore,

247+\boxed{316}=563

Learn by doing: Find a missing addend

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Addition - Missing Value, 3 Digit, 1 Number

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