1st Grade Math Flashcards: Determine Unknown Whole Numbers

What this deck covers

This deck focuses on Determine Unknown Whole Numbers, giving you a quick way to review the definitions, rules, and examples that matter most for 1st Grade Math.

How to use these flashcards

Work through these flashcards in short sessions. Try to answer each prompt before flipping the card, then revisit any cards you miss until the explanation feels automatic.

Flashcard 1: What number makes the equation true: $\Box + 0 = 10$?

Answer: $10$. Adding 0 doesn't change the number.

Flashcard 2: What number makes the equation true: $14 = ? + 9$?

Answer: $5$. Subtract $9$ from $14$ to find the first addend.

Flashcard 3: What number makes the equation true: $9 = ? - 1$?

Answer: $10$. Add 1 to 9 to find the starting number.

Flashcard 4: What number makes the equation true: $\Box - 7 = 2$?

Answer: $9$. Add 7 to 2 to find the starting number.

Flashcard 5: What number makes the equation true: $16 - 9 = \Box$?

Answer: $7$. Subtract 9 from 16 to find the difference.

Flashcard 6: What number makes the equation true: $14 = \Box - 0$?

Answer: $14$. Subtracting 0 doesn't change the number.

Flashcard 7: What number makes the equation true: $? - 5 = 7$?

Answer: $12$. Add $5$ and $7$ to find the starting number.

Flashcard 8: What number makes the equation true: $6 + 6 = \Box$?

Answer: $12$. Add 6 plus 6 to find the sum.

Flashcard 9: What number makes the equation true: $4 = 11 - \Box$?

Answer: $7$. Subtract 4 from 11 to find what was taken away.

Flashcard 10: What number makes the equation true: $\Box = 6 + 2$?

Answer: $8$. Add 6 plus 2 to find the sum.

Flashcard 11: What number makes the equation true: $15 - 8 = ?$?

Answer: $7$. Subtract 8 from 15 to get 7.

Flashcard 12: What number makes the equation true: $0 + ? = 6$?

Answer: $6$. Adding 0 doesn't change the result.

Flashcard 13: What number makes the equation true: $18 = 9 + ?$?

Answer: $9$. Subtract 9 from 18 to find the missing addend.

Flashcard 14: What number makes the equation true: $9 - \Box = 0$?

Answer: $9$. Subtracting a number from itself equals 0.

Flashcard 15: What number makes the equation true: $11 = 4 + ?$?

Answer: $7$. Subtract 4 from 11 to find the missing addend.

Flashcard 16: What number makes the equation true: $\Box - 3 = 5$?

Answer: $8$. Add 3 to 5 to find the starting number.

Flashcard 17: What number makes the equation true: $8 = 14 - ?$?

Answer: $6$. Subtract $8$ from $14$ to find what was subtracted.

Flashcard 18: What number makes the equation true: $10 - \Box = 6$?

Answer: $4$. Subtract 6 from 10 to find what was taken away.

Flashcard 19: What number makes the equation true: $\Box = 17 - 8$?

Answer: $9$. Subtract 8 from 17 to find the difference.

Flashcard 20: What number makes the equation true: $6 + 6 = ?$?

Answer: $12$. Add 6 plus 6 to get 12.

Flashcard 21: What number makes the equation true: $9 + ? = 15$?

Answer: $6$. Subtract $9$ from $15$ to find what to add.

Flashcard 22: What number makes the equation true: $15 = 12 + \Box$?

Answer: $3$. Subtract 12 from 15 to find the missing addend.

Flashcard 23: What number makes the equation true: $16 - 9 = ?$

Answer: $7$. Subtract $9$ from $16$ to get the result.

Flashcard 24: What number makes the equation true: $\Box + 5 = 9$?

Answer: $4$. Subtract 5 from 9 to find the missing addend.

Flashcard 25: What number makes the equation true: $16 - ? = 10$?

Answer: $6$. Subtract 10 from 16 to find what was taken away.

Flashcard 26: What number makes the equation true: $11 - 3 = ?$?

Answer: $8$. Subtract $3$ from $11$ to find the difference.

Flashcard 27: What number makes the equation true: $? + 7 = 12$?

Answer: $5$. Subtract $7$ from $12$ to find the first number.

Flashcard 28: What number makes the equation true: $14 = ? + 5$?

Answer: $9$. Subtract 5 from 14 to find the first addend.

Flashcard 29: What number makes the equation true: $7 + 8 = ?$?

Answer: $15$. Add the two numbers to get the total.

Flashcard 30: What number makes the equation true: $12 - 5 = ?$?

Answer: $7$. Subtract 5 from 12 to get 7.

Flashcard 31: What number makes the equation true: $9 + \Box = 14$?

Answer: $5$. Count up from 9 to 14 to find the missing addend.

Flashcard 32: What number makes the equation true: $18 = \Box + 9$?

Answer: $9$. Subtract 9 from 18 to find the missing addend.

Flashcard 33: What number makes the equation true: $10 = 6 + ?$?

Answer: $4$. Subtract 6 from 10 to find the missing addend.

Flashcard 34: What number makes the equation true: $7 + ? = 7$?

Answer: $0$. Adding 0 doesn't change the number.

Flashcard 35: What number makes the equation true: $13 - ? = 9$?

Answer: $4$. Subtract 9 from 13 to find what was taken away.

Flashcard 36: What number makes the equation true: $4 = ? - 1$?

Answer: $5$. Add $1$ and $4$ to find the first number.

Flashcard 37: What number makes the equation true: $? - 0 = 11$?

Answer: $11$. Subtracting 0 doesn't change the number.

Flashcard 38: What number makes the equation true: $20 - 11 = \Box$?

Answer: $9$. Subtract 11 from 20 to find the difference.

Flashcard 39: What number makes the equation true: $8 + ? = 11$?

Answer: $3$. Add 3 to 8 to get 11.

Flashcard 40: What number makes the equation true: $? - 7 = 2$?

Answer: $9$. Add 7 to 2 to find the starting number.

Flashcard 41: What number makes the equation true: $7 + \Box = 7$?

Answer: $0$. Adding 0 to any number gives the same number.

Flashcard 42: What number makes the equation true: $? + 4 = 9$?

Answer: $5$. Subtract 4 from 9 to find the missing number.

Flashcard 43: What number makes the equation true: $? + 3 = 12$?

Answer: $9$. Subtract 3 from 12 to find the missing addend.

Flashcard 44: What number makes the equation true: $? - 8 = 6$?

Answer: $14$. Add $8$ and $6$ to find the first number.

Flashcard 45: What number makes the equation true: $8 + \Box = 11$?

Answer: $3$. Count up from 8 to 11 to find the missing addend.

Flashcard 46: What number makes the equation true: $? + 6 = 10$?

Answer: $4$. Subtract $6$ from $10$ to find the missing number.

Flashcard 47: What number makes the equation true: $17 - 7 = ?$?

Answer: $10$. Subtract $7$ from $17$ to find the difference.

Flashcard 48: What number makes the equation true: $? + 7 = 15$?

Answer: $8$. Subtract 7 from 15 to find the missing addend.

Flashcard 49: What number makes the equation true: $5 = \Box - 3$?

Answer: $8$. Add 3 to 5 to find the starting number.

Flashcard 50: What number makes the equation true: $13 - \Box = 13$?

Answer: $0$. Subtracting 0 doesn't change the number.

Flashcard 51: What number makes the equation true: $20 - ? = 13$?

Answer: $7$. Subtract 13 from 20 to find what was taken away.

Flashcard 52: What number makes the equation true: $13 = 5 + ?$?

Answer: $8$. Subtract $5$ from $13$ to find the missing addend.

Flashcard 53: What number makes the equation true: $3 = 9 - ?$?

Answer: $6$. Subtract $3$ from $9$ to find what was taken away.

Flashcard 54: What number makes the equation true: $5 = ? - 3$?

Answer: $8$. Add $3$ and $5$ to find the starting number.

Flashcard 55: What number makes the equation true: $18 = ? - 2$?

Answer: $20$. Add $2$ and $18$ to find the starting number.