Complete the following number patterns.
- 761, 674, 587, , 413
- 40, 49, 59, 70, .
- 156, , 172, 176, 178
(a)
761 - 674 = 87
674 - 587 = 87
587 - 87 = 500
Pattern: Keep subtracting 87 from left to right.
(b)
49 - 40 = 9
59 - 49 = 10 (1 is added to 9)
70 - 59 = 11 (1 is added to 10)
11 + 1 = 12
70 + 12 = 82
Pattern: Keep adding 1 to the previous added number from left to right.
(c)
178 - 176 = 2
176 - 172 = 4
172 - 6 = 166
166 - 10 = 156
Pattern: Keep subtracting 2 from the previous subtracted number from right to left.
Answer(s): (a) 500; (b) 82; (c) 166
