Complete the following number patterns.
- 664, 573, 482, , 300
- 20, 30, 41, 53, .
- 119, , 139, 146, 151
(a)
664 - 573 = 91
573 - 482 = 91
482 - 91 = 391
Pattern: Keep subtracting 91 from left to right.
(b)
30 - 20 = 10
41 - 30 = 11 (1 is added to 10)
53 - 41 = 12 (1 is added to 11)
12 + 1 = 13
53 + 13 = 66
Pattern: Keep adding 1 to the previous added number from left to right.
(c)
151 - 146 = 5
146 - 139 = 7
139 - 9 = 130
130 - 11 = 119
Pattern: Keep subtracting 2 from the previous subtracted number from right to left.
Answer(s): (a) 391; (b) 66; (c) 130
