Unknown Numbers

Unknown Numbers

Algebraic Concepts-Day 5

Related Operations

• Addition and subtraction are opposite operations

•  $3+5=8\ so\ 8-5=3$  
  

• Multiplication and Division are opposite operations

•  $3\times5=15\ so\ 15\div5=3$  
  

Important!!!!

• Remember in subtraction and division always start with the BIGGEST number!!!

•  $36\div9=4$  

•  $18-9=9$  

Multiple Choice

Which equation does not belong in the fact family for 3, 4, and 12

• $3\times4=12$

• $12\div3=4$

• $3+4=12$

• $12\div4=3$

Multiple Choice

 $32\div8=?$  Which equation can be used to find the unknown number in the equation below?

•  $8+_?=32$  

•  $8\times?=32$  

•  $32\times8=?$  

•  $8\div?=32$  

Multiple Choice

 $7\times?=42$  

• 5

• 6

• 7

• 8

Multiple Choice

What equation can be used to find 7x?=49

• $49+7=?$

• $49\times7=?$

• $49\div7=?$

• 49-7=?

Multiple Choice

Which equation does not fit into the fact family?

• $7+9=16$

• $9+7=16$

• $16\div7=9$

• $16-9=7$

Multiple Choice

What numbers correctly finish the pattern?

15, 20, 25, 30, 35, ___, ___, ____

• 40, 45, 50

• 40, 50, 45

• 35, 40, 45

• 35, 45, 55

Multiple Choice

What is another way to show 8x6?

• 6x8

• 6+8

• 8+6

• 6+6+6+6

Multiple Choice

What is the rule for the pattern below?

12, 16, 20, 24, 28, 32

• add 4

• add 3

• add 5

• add 6

Multiple Choice

What is NOT a way to write 5 x 4?

• 4 x 5=20

• 4+4+4+4+4=20

• 5+5+5+5=20

• 4+5=20

Multiple Choice

What is 9 x 7=?

• 63

• 54

• 72

• 81

Multiple Choice

What is 9 x 6=?

• 63

• 54

• 72

• 81

Multiple Choice

What is 9 x 9=?

• 63

• 54

• 72

• 81

Multiple Choice

What is 6 x 8=?

• 36

• 48

• 42

• 45

Multiple Choice

What is 6 x 7=?

• 36

• 48

• 42

• 45

Multiple Choice

What is 7 x 7=?

• 42

• 56

• 49

• 63

Multiple Choice

What is 7 x 8=?

• 42

• 56

• 49

• 63

Multiple Choice

What is 6 x 6=?

• 36

• 48

• 42

• 45

Multiple Choice

What is 6 x 6=?

• 36

• 48

• 42

• 45

Multiple Choice

 $56\div8=$  

• 8

• 6

• 7

• 9

Multiple Choice

 $81\div9=$  

• 9

• 8

• 7

• 6

Multiple Choice

 $49\div7=$  

• 9

• 8

• 7

• 6

Multiple Choice

What is 9 x 8=?

• 63

• 54

• 72

• 81