Recall subtraction facts within 20

This knowledge includes fluent recall of whole-number subtraction facts with minuends up to 20, including zero differences, subtracting zero, and related fact families such as $14-6=8$ , $14-8=6$ , and $6+8=14$ . It reflects subtraction as finding a difference or an unknown addend and distinguishes its noncommutative order from addition; it does not extend to larger-number algorithms, decimals, or generalized subtraction.

Detailed Explanation: Recall subtraction facts within 20

Subtraction asks, “How many are left?” or “What number can I add to the subtracted number to get the starting number?”

Example: Find $14-6$ .

Start with $14$ .
Take away $6$ . Think of the related addition fact:
“ $6$ plus what number equals $14$ ?”
Count up from $6$ to $14$ :
$6+4=10$ and $10+4=14$ .
You counted up $8$ altogether, so

14-6=8.

Check your answer with addition:

6+8=14

Remember, subtraction order matters: $14-6$ and $6-14$ do not have the same answer.

Learn by doing: Recall subtraction facts within 20

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Subtraction - Whole Number - Within 20

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Recall subtraction facts within 20

Detailed Explanation: Recall subtraction facts within 20

Learn by doing: Recall subtraction facts within 20

Practice with unlimited practice problems

Practice:

Subtraction - Whole Number - Within 20