Complete the following number patterns.
- 915, 865, 815, , 715
- 27, 35, 44, 54, .
- 165, , 180, 184, 186
(a)
915 - 865 = 50
865 - 815 = 50
815 - 50 = 765
Pattern: Keep subtracting 50 from left to right.
(b)
35 - 27 = 8
44 - 35 = 9 (1 is added to 8)
54 - 44 = 10 (1 is added to 9)
10 + 1 = 11
54 + 11 = 65
Pattern: Keep adding 1 to the previous added number from left to right.
(c)
186 - 184 = 2
184 - 180 = 4
180 - 6 = 174
174 - 9 = 165
Pattern: Keep subtracting 2 from the previous subtracted number from right to left.
Answer(s): (a) 765; (b) 65; (c) 174
