Consecutive Numbers

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Consecutive Numbers

Task 1

Problem 1

Write down 3 consecutive numbers. Square the middle one. Multiply the

first and the third number. Compare the two numbers, what do you

notice?

Problem 2

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Write down two consecutive numbers. Square both of the numbers and

find the difference between the squares. What do you notice?

Problem 1

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I am going to investigate several sets of three consecutive numbers to

see if the square of the middle is related to the product of the outer

two numbers in any way.

9,10,11

10²= 100

9x11= 99

3,4,5

I notice that the square of the middle number is always one more than

the product of the other numbers.

4²=16

3x5=15

18,19,20

19²=361

18x20=360

1,2,3

2²=4

1x3=3

30,31,32

31²=961

30x32=960

1st Number

2nd Number

3rd Number

2nd number squared

1st number x 3rd number

9

10

11

100

99

3

4

5

16

15

18

19

20

361

360

1

2

3

4

3

30

31

32

961

960

I have put my results in a table so that they will be easier to

analyse and compare.

When you take three consecutive numbers, square the middle and

multiply the outer two, the squared number will always be one more

than the product of the outer two.

If this rule is correct, then by using the three consecutive numbers:

101,102,103, I predict that 102² will equal one more than 101x103.

101,102,103

102²=10404

101x103= 10403

My prediction was correct as 102², 10404, is one more than 101x103,

10403.

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