Solving Number Problems: Odd Numbers and Doubling

In this worksheet, students express an odd number as 2n+1 and then asking whether n is odd or even.

Key stage:  KS 2

Curriculum topic:   Maths and Numerical Reasoning

Curriculum subtopic:   Equations and Algebra

Difficulty level:

QUESTION 1 of 10

In this worksheet, we will learn how to express an odd number as "double a number plus one" and then identify whether the result is an odd or even number.

For Example:

Question:
Write this odd number as "double a number plus one". Then say whether your answer is odd or even.

209   =   2  x    ______   +  1

If you take one away from 209, you get 208. If you halve this number, you get 104. So

209   =   2  x  104  +  1

which is the same as "double 104 plus one".

The number 104 is an even number, since it is divisible by 2.

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

207   =   2  x    ______   +  1

103 (Odd)

103 (Even)

206 (Odd)

206 (Even)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

401   =   2  x    ______   +  1

200 (Odd)

200 (Even)

100 (Odd)

100 (Even)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

685   =   2  x    ______   +  1

342 (Even)

342 (Odd)

321 (Odd)

321 (Even)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

161   =   2  x    ______   +  1

90 (Even)

90 (Odd)

80 (Even)

80 (Odd)

Write these odd numbers as double a number plus one. Then say whether your answer is odd or even.

15   =   2  x    ______   +  1

4 (Odd)

4 (Even)

7 (Odd)

7 (Even)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

345   =   2  x    ______   +  1

172 (Even)

172 (Odd)

152(Even)

152 (Odd)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

967  =   2  x    ______   +  1

483 (Odd)

483 (Even)

485 (Odd)

485 (Even)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

835   =   2  x    ______   +  1

419(Even)

419 (Odd)

417 (Even)

417 (Odd)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

969   =   2  x    ______   +  1

484 (Even)

484 (Odd)

592 (Even)

592 (Odd)

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

877   =   2  x    ______   +  1

438 (Odd)

438 (Even)

219 (Odd)

219 (Even)

• Question 1

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

207   =   2  x    ______   +  1

103 (Odd)
• Question 2

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

401   =   2  x    ______   +  1

200 (Even)
• Question 3

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

685   =   2  x    ______   +  1

342 (Even)
• Question 4

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

161   =   2  x    ______   +  1

80 (Even)
• Question 5

Write these odd numbers as double a number plus one. Then say whether your answer is odd or even.

15   =   2  x    ______   +  1

7 (Odd)
• Question 6

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

345   =   2  x    ______   +  1

172 (Even)
• Question 7

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

967  =   2  x    ______   +  1

483 (Odd)
• Question 8

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

835   =   2  x    ______   +  1

417 (Odd)
• Question 9

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

969   =   2  x    ______   +  1

484 (Even)
• Question 10

Write this odd number as double a number plus one.  Then say whether your answer is odd or even.

877   =   2  x    ______   +  1

438 (Even)
---- OR ----

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