Common Core: 3rd Grade Math : Operations & Algebraic Thinking

Study concepts, example questions & explanations for Common Core: 3rd Grade Math

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Example Questions

Example Question #223 : Numbers And Operations

\displaystyle \frac{\begin{array}[b]{r}2\\ \times 10\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 30

\displaystyle 40

\displaystyle 50

\displaystyle 20

\displaystyle 10

Correct answer:

\displaystyle 20

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 2\times10 means adding \displaystyle 10 two times. 

\displaystyle 10+10=20 and \displaystyle 2\times10=20

Or we can think of this as grouping objects. We have \displaystyle 2 groups, with \displaystyle 10 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #224 : Numbers And Operations

\displaystyle \frac{\begin{array}[b]{r}1\\ \times 8\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 8

\displaystyle 16

\displaystyle 24

\displaystyle 32

\displaystyle 40

Correct answer:

\displaystyle 8

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 1\times8 means adding \displaystyle 8 one times. 

\displaystyle 8=8 and \displaystyle 1\times8=8

Or we can think of this as grouping objects. We have \displaystyle 1 group, with \displaystyle 8 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #121 : How To Multiply

\displaystyle \frac{\begin{array}[b]{r}3\\ \times 2\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 18

\displaystyle 6

\displaystyle 9

\displaystyle 15

\displaystyle 12

Correct answer:

\displaystyle 6

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 3\times2 means adding \displaystyle 2 three times. 

\displaystyle 2+2+2=6 and \displaystyle 3\times2=6

Or we can think of this as grouping objects. We have \displaystyle 3 groups, with \displaystyle 2 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #226 : Numbers And Operations

\displaystyle \frac{\begin{array}[b]{r}4\\ \times 4\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 16

\displaystyle 20

\displaystyle 24

\displaystyle 12

\displaystyle 28

Correct answer:

\displaystyle 16

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 4\times4 means adding \displaystyle 4 four times. 

\displaystyle 4+4+4+4=16 and \displaystyle 4\times4=16

Or we can think of this as grouping objects. We have \displaystyle 4 groups, with \displaystyle 4 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #227 : Numbers And Operations

\displaystyle \frac{\begin{array}[b]{r}6\\ \times 7\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 42

\displaystyle 30

\displaystyle 36

\displaystyle 18

\displaystyle 24

Correct answer:

\displaystyle 42

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 6\times7 means adding \displaystyle 7 six times. 

\displaystyle 7+7+7+7+7+7=42 and \displaystyle 6\times7=42

Or we can think of this as grouping objects. We have \displaystyle 6 groups, with \displaystyle 7 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #21 : Operations & Algebraic Thinking

\displaystyle \frac{\begin{array}[b]{r}7\\ \times1 2\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 70

\displaystyle 56

\displaystyle 84

\displaystyle 63

\displaystyle 77

Correct answer:

\displaystyle 84

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 7\times12 means adding \displaystyle 12 seven times. 

\displaystyle 12+12+12+12+12+12+12=84 and \displaystyle 7\times12=84

Or we can think of this as grouping objects. We have \displaystyle 7 groups, with \displaystyle 12 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #22 : Operations & Algebraic Thinking

\displaystyle \frac{\begin{array}[b]{r}8\\ \times 6\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 32

\displaystyle 56

\displaystyle 40

\displaystyle 64

\displaystyle 48

Correct answer:

\displaystyle 48

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 8\times6 means adding \displaystyle 6 eight times. 

\displaystyle 6+6+6+6+6+6+6+6=48 and \displaystyle 8\times6=48

Or we can think of this as grouping objects. We have \displaystyle 8 groups, with \displaystyle 6 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #122 : How To Multiply

\displaystyle \frac{\begin{array}[b]{r}9\\ \times 1\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 9

\displaystyle 7

\displaystyle 8

\displaystyle 6

\displaystyle 5

Correct answer:

\displaystyle 9

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 9\times1 means adding \displaystyle 1 nine times. 

\displaystyle 1+1+1+1+1+1+1+1+1=9 and \displaystyle 9\times1=9

Or we can think of this as grouping objects. We have \displaystyle 9 groups, with \displaystyle 1 object in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #23 : Operations & Algebraic Thinking

\displaystyle \frac{\begin{array}[b]{r}10\\ \times 4\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 30

\displaystyle 40

\displaystyle 10

\displaystyle 20

\displaystyle 50

Correct answer:

\displaystyle 40

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 10\times4 means adding \displaystyle 4 ten times. 

\displaystyle 4+4+4+4+4+4+4+4+4+4=40 and \displaystyle 10\times4=40

Or we can think of this as grouping objects. We have \displaystyle 10 groups, with \displaystyle 4 objects in each group. We can count up the total number of objects, in this case triangles. 

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Example Question #21 : Interpret Products Of Whole Numbers: Ccss.Math.Content.3.Oa.A.1

\displaystyle \frac{\begin{array}[b]{r}11\\ \times 5\end{array}}{ \ \ \ \space}

 

Possible Answers:

\displaystyle 55

\displaystyle 77

\displaystyle 88

\displaystyle 66

\displaystyle 44

Correct answer:

\displaystyle 55

Explanation:

Multiplication can be thought of as repeated addition, or as objects in a group. 

\displaystyle 11\times5 means adding \displaystyle 5 eleven times. 

\displaystyle 5+5+5+5+5+5+5+5+5+5+5=55 and \displaystyle 11\times5=55

Or we can think of this as grouping objects. We have \displaystyle 11 groups, with \displaystyle 5 objects in each group. We can count up the total number of objects, in this case triangles. 

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