Chapter 2 Review

What is a conjecture?

• An educated guess based off observations or patterns

• A conditional statement

• An if-then statement

• An example that proves a statement is false

What is a counterexample?

• An educated guess based off observations or patterns

• A conditional statement

• An if-then statement

• An example that proves a statement is false

Write a conjecture for the following pattern: "To find the next term,____"

4, 8, 12, 16, 20, 24, __, __, __

Tags

CCSS.3.OA.D.9

Write a conjecture for the following pattern: "To find the next term,____"

4:05, 4:30, 4:55, 5:20, ___, ___, ___

Tags

CCSS.4.OA.C.5

Determine if the following conjecture is true or false.

All numbers that end in 7 are prime numbers (cannot be divided by anything besides 1 and itself).

• True

• False

Tags

CCSS.4.OA.B.4

Which is a counterexample to the previous question?

"All numbers that end in 7 are prime"

• 17

• 27

• 37

• 97

Tags

CCSS.4.OA.B.4

Determine if the conjecture is true or false:

If you multiply two numbers, the answer is always larger than both numbers.

• True

• False

Tags

CCSS.5.NBT.A.2

Which of the following are counterexamples? (SELECT ALL THAT APPLY)

"If you multiply two numbers, the answer is always larger than both numbers."

Answer explanation

0*100 = 0 (0 is not larger than 0 or 100)

1*1 = 1 (1 is not larger than 1)

-1*10 = -10 (-10 is not larger than -1 or 10)

10*(1/2) = 5 (5 is not larger than 10)

Tags

CCSS.7.NS.A.2A

CCSS.7.NS.A.2B

The following statement is FALSE. Give a counterexample that proves why conjecture is wrong.

"If you multiply any number by -1, the answer is less than the original number"

Tags

CCSS.5.NBT.A.2

Conditional Statements can be written as if-then statements. Usually the "if" part contains the (1)_____, and the "then" part contains the (2)_____

• 1) hypothesis

  2) conclusion

• 1) conclusion

  2) hypothesis

Tags

CCSS.L.2.1F

CCSS.L.8.1C

CCSS.L.8.3A