Complete the following number patterns.
- 985, 918, 851, , 717
- 43, 49, 56, 64, .
- 98, , 112, 117, 120
(a)
985 - 918 = 67
918 - 851 = 67
851 - 67 = 784
Pattern: Keep subtracting 67 from left to right.
(b)
49 - 43 = 6
56 - 49 = 7 (1 is added to 6)
64 - 56 = 8 (1 is added to 7)
8 + 1 = 9
64 + 9 = 73
Pattern: Keep adding 1 to the previous added number from left to right.
(c)
120 - 117 = 3
117 - 112 = 5
112 - 7 = 105
105 - 7 = 98
Pattern: Keep subtracting 2 from the previous subtracted number from right to left.
Answer(s): (a) 784; (b) 73; (c) 105
