Straws are used to make the figures as shown.
- How many straws are used to make Figure 12?
- Which figure requires the use of 148 straws?
(a)
Pattern for the number of straws
Figure 1: 1 x 6 - 2 = 4
Figure 2: 2 x 6 - 2 = 10
Figure 3: 3 x 6 - 2 = 16
Figure 4: 4 x 6 - 2 = 22
Formula:
Number of straws used = Figure Number x 6 - 2
Number of straws used to make Figure 12
= 12 x 6 - 2
= 72 - 2
= 70
(b)
Figure Number x 6 - 2 = 148
Figure Number x 6 = 148 + 2
Figure Number x 6 = 150
Figure Number = 150 ÷ 6
Figure Number = 25
Figure Number that requires the use of 148 straws = 25
Answer(s): (a) 70; (b) 25