Subtraction As An Unknown-Addend Problem - 1st Grade Math
Card 1 of 15
What is the missing number $x$ in $5+x=9$ (so $9-5=x$)?
What is the missing number $x$ in $5+x=9$ (so $9-5=x$)?
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$4$. Find what number added to $5$ makes $9$.
$4$. Find what number added to $5$ makes $9$.
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What is the missing number $x$ in $8+x=10$ (so $10-8=x$)?
What is the missing number $x$ in $8+x=10$ (so $10-8=x$)?
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$2$. Find what number added to $8$ makes $10$.
$2$. Find what number added to $8$ makes $10$.
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What does $a-b$ mean when you rewrite it as an unknown-addend equation?
What does $a-b$ mean when you rewrite it as an unknown-addend equation?
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$b+x=a$. Subtraction $a-b$ asks what number added to $b$ gives $a$.
$b+x=a$. Subtraction $a-b$ asks what number added to $b$ gives $a$.
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What is the missing number $x$ in $13+x=20$ (so $20-13=x$)?
What is the missing number $x$ in $13+x=20$ (so $20-13=x$)?
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$7$. Find what number added to $13$ makes $20$.
$7$. Find what number added to $13$ makes $20$.
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What is the missing number $x$ in $17+x=19$ (so $19-17=x$)?
What is the missing number $x$ in $17+x=19$ (so $19-17=x$)?
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$2$. Find what number added to $17$ makes $19$.
$2$. Find what number added to $17$ makes $19$.
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What is the missing number $x$ in $9+x=9$ (so $9-9=x$)?
What is the missing number $x$ in $9+x=9$ (so $9-9=x$)?
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$0$. Any number minus itself equals zero.
$0$. Any number minus itself equals zero.
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Which subtraction matches the unknown-addend equation $6+x=10$?
Which subtraction matches the unknown-addend equation $6+x=10$?
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$10-6=x$. The subtraction that finds what added to $6$ gives $10$.
$10-6=x$. The subtraction that finds what added to $6$ gives $10$.
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What is the missing number $x$ in $1+x=10$ (so $10-1=x$)?
What is the missing number $x$ in $1+x=10$ (so $10-1=x$)?
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$9$. Find what number added to $1$ makes $10$.
$9$. Find what number added to $1$ makes $10$.
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What is the missing number $x$ in $14+x=18$ (so $18-14=x$)?
What is the missing number $x$ in $14+x=18$ (so $18-14=x$)?
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$4$. Find what number added to $14$ makes $18$.
$4$. Find what number added to $14$ makes $18$.
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What is the missing number $x$ in $8+x=16$ (so $16-8=x$)?
What is the missing number $x$ in $8+x=16$ (so $16-8=x$)?
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$8$. Find what number added to $8$ makes $16$.
$8$. Find what number added to $8$ makes $16$.
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What is the missing number $x$ in $2+x=9$ (so $9-2=x$)?
What is the missing number $x$ in $2+x=9$ (so $9-2=x$)?
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$7$. Find what number added to $2$ makes $9$.
$7$. Find what number added to $2$ makes $9$.
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What is the missing number $x$ in $11+x=11$ (so $11-11=x$)?
What is the missing number $x$ in $11+x=11$ (so $11-11=x$)?
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$0$. Any number minus itself equals zero.
$0$. Any number minus itself equals zero.
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What is the missing number $x$ in $12+x=16$ (so $16-12=x$)?
What is the missing number $x$ in $12+x=16$ (so $16-12=x$)?
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$4$. Find what number added to $12$ makes $16$.
$4$. Find what number added to $12$ makes $16$.
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What is the missing number $x$ in $3+x=15$ (so $15-3=x$)?
What is the missing number $x$ in $3+x=15$ (so $15-3=x$)?
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$12$. Find what number added to $3$ makes $15$.
$12$. Find what number added to $3$ makes $15$.
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What is the missing number $x$ in $10+x=14$ (so $14-10=x$)?
What is the missing number $x$ in $10+x=14$ (so $14-10=x$)?
Tap to reveal answer
$4$. Find what number added to $10$ makes $14$.
$4$. Find what number added to $10$ makes $14$.
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