Common Core: 1st Grade Math : Find the Missing Number in Addition and Subtraction Equations: CCSS.MATH.CONTENT.1.OA.D.8

Study concepts, example questions & explanations for Common Core: 1st Grade Math

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Example Questions

Example Question #721 : Operations & Algebraic Thinking

Fill in the blank. 

\(\displaystyle 8+\)__________\(\displaystyle =13\) 

Possible Answers:

\(\displaystyle 4\)

\(\displaystyle 6\)

\(\displaystyle 7\)

\(\displaystyle 8\)

\(\displaystyle 5\)

Correct answer:

\(\displaystyle 5\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 13-8=5\), which means \(\displaystyle 8+5=13\).

Example Question #1511 : Numbers And Operations

Fill in the blank. 

\(\displaystyle 9+\)__________\(\displaystyle =11\) 

Possible Answers:

\(\displaystyle 6\)

\(\displaystyle 5\)

\(\displaystyle 2\)

\(\displaystyle 3\)

\(\displaystyle 4\)

Correct answer:

\(\displaystyle 2\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 11-9=2\), which means \(\displaystyle 9+2=11\).

Example Question #1512 : Numbers And Operations

Fill in the blank. 

\(\displaystyle 10+\)__________\(\displaystyle =13\) 

Possible Answers:

\(\displaystyle 6\)

\(\displaystyle 4\)

\(\displaystyle 3\)

\(\displaystyle 7\)

\(\displaystyle 5\)

Correct answer:

\(\displaystyle 3\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 13-10=3\), which means \(\displaystyle 10+3=13\).

Example Question #1513 : Numbers And Operations

Fill in the blank. 

\(\displaystyle 12+\)__________\(\displaystyle =20\) 

Possible Answers:

\(\displaystyle 5\)

\(\displaystyle 8\)

\(\displaystyle 4\)

\(\displaystyle 7\)

\(\displaystyle 6\)

Correct answer:

\(\displaystyle 8\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 20-12=8\), which means \(\displaystyle 20+12=8\).

Example Question #725 : Operations & Algebraic Thinking

Fill in the blank. 

\(\displaystyle 1+\)__________\(\displaystyle =20\) 

Possible Answers:

\(\displaystyle 19\)

\(\displaystyle 20\)

\(\displaystyle 17\)

\(\displaystyle 16\)

\(\displaystyle 18\)

Correct answer:

\(\displaystyle 19\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 20-1=19\), which means \(\displaystyle 1+19=20\).

Example Question #1514 : Numbers And Operations

Fill in the blank. 

\(\displaystyle 1+\)__________\(\displaystyle =13\) 

Possible Answers:

\(\displaystyle 10\)

\(\displaystyle 9\)

\(\displaystyle 12\)

\(\displaystyle 11\)

\(\displaystyle 8\)

Correct answer:

\(\displaystyle 12\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 13-1=12\), which means \(\displaystyle 1+12=13\).

Example Question #1515 : Numbers And Operations

Fill in the blank. 

\(\displaystyle 2+\)__________\(\displaystyle =12\) 

Possible Answers:

\(\displaystyle 10\)

\(\displaystyle 11\)

\(\displaystyle 8\)

\(\displaystyle 9\)

\(\displaystyle 7\)

Correct answer:

\(\displaystyle 10\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 12-2=10\), which means \(\displaystyle 2+10=12\)

Example Question #141 : Find The Missing Number In Addition And Subtraction Equations: Ccss.Math.Content.1.Oa.D.8

Fill in the blank. 

\(\displaystyle 3+\)__________\(\displaystyle =4\) 

Possible Answers:

\(\displaystyle 2\)

\(\displaystyle 4\)

\(\displaystyle 0\)

\(\displaystyle 3\)

\(\displaystyle 1\)

Correct answer:

\(\displaystyle 1\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 4-3=1\), which means \(\displaystyle 3+1=4\).

Example Question #141 : Find The Missing Number In Addition And Subtraction Equations: Ccss.Math.Content.1.Oa.D.8

Fill in the blank. 

\(\displaystyle 3+\)__________\(\displaystyle =20\) 

Possible Answers:

\(\displaystyle 16\)

\(\displaystyle 15\)

\(\displaystyle 18\)

\(\displaystyle 14\)

\(\displaystyle 17\)

Correct answer:

\(\displaystyle 17\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 20-3=17\), which means \(\displaystyle 3+17=20\).

Example Question #142 : Find The Missing Number In Addition And Subtraction Equations: Ccss.Math.Content.1.Oa.D.8

Fill in the blank. 

\(\displaystyle 4+\)__________\(\displaystyle =16\) 

Possible Answers:

\(\displaystyle 13\)

\(\displaystyle 11\)

\(\displaystyle 10\)

\(\displaystyle 12\)

\(\displaystyle 14\)

Correct answer:

\(\displaystyle 12\)

Explanation:

To find the missing piece of an addition problem, you can take the biggest number minus the smallest number. \(\displaystyle 16-4=12\), which means \(\displaystyle 4+12=16\).

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