Investigation 1: Is there a pattern in the decimal form of ninths?
Hypothesis:
As 7/9, 0.77777…, and 8/9, 0.88888…, are very similar in their decimal forms, I believe that there will be a pattern in the decimal form of ninths.
Results:
Number of Ninths | Decimal | Does It Follow The Pattern? |
1 | 0.11 | Yes |
2 | 0.22 | Yes |
3 | 0.33 | Yes |
4 | 0.44 | Yes |
5 | 0.56 | Yes |
6 | 0.67 | Yes |
7 | 0.78 | Yes |
8 | 0.89 | Yes |
9 | 1.00 | Yes |
10 | 1.11 | Yes |
11 | 1.22 | Yes |
12 | 1.33 | Yes |
13 | 1.44 | Yes |
14 | 1.56 | Yes |
15 | 1.67 | Yes |
16 | 1.78 | Yes |
17 | 1.89 | Yes |
18 | 2.00 | Yes |
19 | 2.11 | Yes |
20 | 2.22 | Yes |
21 | 2.33 | Yes |
22 | 2.44 | Yes |
23 | 2.56 | Yes |
24 | 2.67 | Yes |
25 | 2.78 | Yes |
26 | 2.89 | Yes |
27 | 3.00 | Yes |
Conclusion:
The whole numbers (0, 1 and 2) show the amount of complete nines. For example 9 ninths is equal to 1 complete 9 and 18 ninths is equal to 2. This is why they are shown as 1.00 and 2.00.
The numbers following the decimal place show the fraction of the whole nine remaining. These decimals, except 0, are recurring, making the number infinitely long. However, these numbers have been rounded up and down to 2 decimal places. Numbers like 1.89 and 0.56 have been rounded up and the second decimal is always 1 more than the first. Meanwhile, numbers rounded down repeat the first decimal and include 1.22 and 0.44.
This reveals a pattern in the decimal form of ninths. For 1 to 8 ninths, the recurring number after the decimal place is the same as the amount of ninths. From 10 to 17 ninths, the decimal is 1 more than the amount of ninths shown in the ones column. From 19 to 26 ninths the decimal is two more.
Investigation 2: Does the pattern in the decimal form of ninths reset?
Hypothesis:
The pattern described above will keep going with the difference between the first decimal and ones column of ninths increasing by 1 after every whole 9 until it reaches 90 ninths. In theory, the pattern should restart here due to 90 being a multiple of 9 that ends in 0.
Results:
Number Of Ninths | Decimal | Does It Follow The Pattern |
27 | 3.00 | Yes |
28 | 3.11 | Yes |
29 | 3.22 | Yes |
30 | 3.33 | Yes |
31 | 3.44 | Yes |
32 | 3.56 | Yes |
33 | 3.67 | Yes |
34 | 3.78 | Yes |
35 | 3.89 | Yes |
36 | 4.00 | Yes |
37 | 4.11 | Yes |
38 | 4.22 | Yes |
39 | 4.33 | Yes |
40 | 4.44 | Yes |
41 | 4.56 | Yes |
42 | 4.67 | Yes |
43 | 4.78 | Yes |
44 | 4.89 | Yes |
45 | 5.00 | Yes |
46 | 5.11 | Yes |
47 | 5.22 | Yes |
48 | 5.33 | Yes |
49 | 5.44 | Yes |
50 | 5.56 | Yes |
51 | 5.67 | Yes |
52 | 5.78 | Yes |
53 | 5.89 | Yes |
54 | 6.00 | Yes |
55 | 6.11 | Yes |
56 | 6.22 | Yes |
57 | 6.33 | Yes |
58 | 6.44 | Yes |
59 | 6.56 | Yes |
60 | 6.67 | Yes |
61 | 6.78 | Yes |
62 | 6.89 | Yes |
63 | 7.00 | Yes |
64 | 7.11 | Yes |
65 | 7.22 | Yes |
66 | 7.33 | Yes |
67 | 7.44 | Yes |
68 | 7.56 | Yes |
69 | 7.67 | Yes |
70 | 7.78 | Yes |
71 | 7.89 | Yes |
72 | 8.00 | Yes |
73 | 8.11 | Yes |
74 | 8.22 | Yes |
75 | 8.33 | Yes |
76 | 8.44 | Yes |
77 | 8.56 | Yes |
78 | 8.67 | Yes |
79 | 8.78 | Yes |
80 | 8.89 | Yes |
81 | 9.00 | Yes |
82 | 9.11 | Yes |
83 | 9.22 | Yes |
84 | 9.33 | Yes |
85 | 9.44 | Yes |
86 | 9.56 | Yes |
87 | 9.67 | Yes |
88 | 9.78 | Yes |
89 | 9.89 | Yes |
90 | 10.00 | No |
91 | 10.11 | Yes |
92 | 10.22 | Yes |
93 | 10.33 | Yes |
94 | 10.44 | Yes |
95 | 10.56 | Yes |
96 | 10.67 | Yes |
97 | 10.78 | Yes |
98 | 10.89 | Yes |
99 | 11.00 | Yes |
Conclusion:
The table above shows that the pattern does keep going until 90 ninths, with the difference between the ones column of ninths and decimal being 9 between 82 and 89 ninths. Then, the difference resets and becomes 0 once more upon reaching 90 ninths.