Study the table carefully.
- How many dots are there in Figure 9?
- If there are 26 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 9
= (9 - 1) x 5 + 1
= 41
(b)
Figure number for 26 dots
(Figure number - 1) x 5 + 1 = 26
(Figure number - 1) x 5 = 26 - 1 = 25
(Figure number - 1) = 25 ÷ 5 = 5
Figure number = 5 + 1 = 6
Answer(s): (a) 41; (b) 6