Complete the following number patterns.
- 642, 582, 522, , 402
- 23, 33, 44, 56, .
- 149, , 168, 174, 178
(a)
642 - 582 = 60
582 - 522 = 60
522 - 60 = 462
Pattern: Keep subtracting 60 from left to right.
(b)
33 - 23 = 10
44 - 33 = 11 (1 is added to 10)
56 - 44 = 12 (1 is added to 11)
12 + 1 = 13
56 + 13 = 69
Pattern: Keep adding 1 to the previous added number from left to right.
(c)
178 - 174 = 4
174 - 168 = 6
168 - 8 = 160
160 - 11 = 149
Pattern: Keep subtracting 2 from the previous subtracted number from right to left.
Answer(s): (a) 462; (b) 69; (c) 160
