Study the series of figures carefully
- Find the number of sticks needed in Figure 40.
- Find the number of dots needed when 593 sticks are used.
(a)
Pattern for the number of sticks
Figure 1: 1 x 5 - 2 = 3 sticks
Figure 2: 2 x 5 - 2 = 7 sticks
Figure 3: 3 x 5 - 2 = 13 sticks
Formula:
Number of sticks needed = Figure number x 5 - 2
Number of sticks needed in Figure 40
= 40 x 5 - 2
= 198
(b)
Figure number x 5 - 2 = 593
Figure number x 5 = 593 + 2 = 595
Figure number = 595 ÷ 5 = 119
Pattern for the number of dots
Figure 1: 1 x 2 + 1 = 3 dots
Figure 2: 2 x 2 + 1 = 5 dots
Figure 3: 3 x 2 + 1 = 7 dots
Formula:
Number of dots = Figure number x 2 + 1
Number of dots needed in Figure 119
= 119 x 2 + 1
= 239
Answer(s): (a) 198; (b) 239
