Conjectures and Counterexamples

A counterexample is an example that proves a conjecture to be true.

• True

• False

Tags

CCSS.W.11-12.2D

CCSS.L.11-12.6

CCSS.L.9-10.6

CCSS.W.8.2D

CCSS.W.9-10.2D

To fully disprove a conjecture, one needs to find only ONE counterexample.

• True

• False

Tags

CCSS.L.11-12.4C

CCSS.L.6.4C

CCSS.L.7.4C

CCSS.L.8.4C

CCSS.L.9-10.4C

A concluding statement reached using inductive reasoning is called a _______

• compound statement

• conjecture

• condition

• counterexample

Tags

CCSS.7.SP.A.2

How many counters would come next?

• 5
• 7
• 9
• 11

Tags

CCSS.4.OA.C.5

How can you prove a conjecture is false?

• Counterexample
• Not Possible
• Patterns

Tags

CCSS.HSS.CP.A.3

CCSS.HSS.CP.A.5

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

• goldfish
• frog
• elephant
• cat

Tags

CCSS.W.11-12.2D

CCSS.L.6.5B

CCSS.L.8.5B

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

Which is a counterexample of: Any number divisible by 2 is divisible by 4.

• 15÷2
• 20÷4
• 16÷4
• 10÷2

Tags

CCSS.5.OA.B.3

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

Which is a counterexample to the following statement?

If it's sunny outside, then the weather is warm.

• sunday night

• 3am

• sunny day during winter

• the oven

Tags

CCSS.W.11-12.2D

CCSS.L.11-12.6

CCSS.L.9-10.6

CCSS.W.8.2D

CCSS.W.9-10.2D