Complete the following number patterns.
- 805, 738, 671, , 537
- 30, 40, 51, 63, .
- 38, , 58, 65, 70
(a)
805 - 738 = 67
738 - 671 = 67
671 - 67 = 604
Pattern: Keep subtracting 67 from left to right.
(b)
40 - 30 = 10
51 - 40 = 11 (1 is added to 10)
63 - 51 = 12 (1 is added to 11)
12 + 1 = 13
63 + 13 = 76
Pattern: Keep adding 1 to the previous added number from left to right.
(c)
70 - 65 = 5
65 - 58 = 7
58 - 9 = 49
49 - 11 = 38
Pattern: Keep subtracting 2 from the previous subtracted number from right to left.
Answer(s): (a) 604; (b) 76; (c) 49
