Study the table carefully.
- How many dots are there in Figure 17?
- If there are 46 dots, what Is the Figure number?
(a)
Pattern for the number of dots
Figure 1: (1 - 1) x 5 + 1 = 1
Figure 2: (2 - 1) x 5 + 1 = 6
Figure 3: (3 - 1) x 5 + 1 = 11
Figure 4: (4 - 1) x 5 + 1 = 16
Formula:
Number of dots = (Figure number - 1) x 5 + 1
Number of dots in Figure 17
= (17 - 1) x 5 + 1
= 81
(b)
Figure number for 46 dots
(Figure number - 1) x 5 + 1 = 46
(Figure number - 1) x 5 = 46 - 1 = 45
(Figure number - 1) = 45 ÷ 5 = 9
Figure number = 9 + 1 = 10
Answer(s): (a) 81; (b) 10
