Straws are used to make the figures as shown.
- How many straws are used to make Figure 11?
- Which figure requires the use of 154 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 11
= 11 x 6 - 2
= 66 - 2
= 64
(b)
Figure Number x 6 - 2 = 154
Figure Number x 6 = 154 + 2
Figure Number x 6 = 156
Figure Number = 156 ÷ 6
Figure Number = 26
Figure Number that requires the use of 154 straws = 26
Answer(s): (a) 64; (b) 26