Complete the following number patterns.
- 738, 648, 558, , 378
- 47, 55, 64, 74, .
- 46, , 63, 69, 73
(a)
738 - 648 = 90
648 - 558 = 90
558 - 90 = 468
Pattern: Keep subtracting 90 from left to right.
(b)
55 - 47 = 8
64 - 55 = 9 (1 is added to 8)
74 - 64 = 10 (1 is added to 9)
10 + 1 = 11
74 + 11 = 85
Pattern: Keep adding 1 to the previous added number from left to right.
(c)
73 - 69 = 4
69 - 63 = 6
63 - 8 = 55
55 - 9 = 46
Pattern: Keep subtracting 2 from the previous subtracted number from right to left.
Answer(s): (a) 468; (b) 85; (c) 55
