Conditional Statements & Counterexamples

If an animal is furry, then it is a hamster. What would be an appropriate counterexample?

• goldfish
• frog
• elephant
• cat

Tags

CCSS.RI.11-12.2

CCSS.RI.9-10.1

CCSS.RL.11-12.1

CCSS.RL.8.1

CCSS.RL.9-10.1

The product of two negative numbers is greater than the sum of the two numbers. What is an appropriate counterexample?

• -3 and -3
• True. There is no counterexample
• -1 and -1
• 4 and 6

Tags

CCSS.7.NS.A.2A

CCSS.7.NS.A.2B

If it is a line, then it has a positive slope. What is an appropriate counterexample?

• y = -4x
• y = 6x
• y = 1/5x + 5
• y = 2x - 6

Tags

CCSS.8.EE.B.5

If it is a fraction, then it is a number between zero and one. What is an appropriate counterexample?

• 2/3
• 4/5
• 1/2
• 3/2

Tags

CCSS.6.NS.C.7A

CCSS.6.NS.C.7B

If it is an angle, then it is acute. What is an appropriate counterexample?

• 70⁰
• 45⁰
• 120⁰
• True. There is no counterexample.

Tags

CCSS.7.G.B.5

If it is a number, then it is either positive or negative. What is an appropriate counterexample?

• 10
• -2
• 0
• True. There is no counterexample.

Tags

CCSS.6.NS.C.5

If a three-dimensional solid has a circular base, then it is a cone. What is an appropriate counterexample?

• prism
• pyramid
• cube
• cylinder

Tags

CCSS.1.G.A.1

CCSS.2.G.A.1

If it is a vehicle, then it is a Ford. What is an appropriate counterexample?

• Ford Mustang
• Dodge Charger
• Ford F150
• Both A and C are counterexamples.

Tags

CCSS.HSS.CP.A.5

If a shape is round, then it is a circle. What is an appropriate counterexample?

• hexagon
• oval
• triangle
• square

Tags

CCSS.1.G.A.1

CCSS.2.G.A.1

The opposite of any number is smaller than the original number. What is an appropriate counterexample?

• original: -1 
  opposite: 1
• original: 2
  opposite: -2
• original: 0
  opposite: 0
• True. There is no counterexample.

Tags

CCSS.6.NS.C.6A