Look at the figures. The rectangles represent tables and the dots represent chairs for guests at a party.
- How many tables will Figure 4 have?
- How many chairs will Figure 10 have?
- If there are 86 guests at the party, how many tables will be needed?
(a)
Pattern for the number of tables
Figure 1: 1
Figure 2: 2
Figure 3: 3
Formula
Number of tables = Figure number
Number of tables for Figure 4 = 4
(b)
Pattern for the number of chairs
Figure 1: 1 x 4 + 2 = 6
Figure 2: 2 x 4 + 2 = 10
Figure 3: 3 x 4 + 2 = 14
Formula
Number of chairs = Figure number x 4 + 2
Number of chairs for Figure 10
= 10 x 4 + 2
= 42
(c)
86 guests: 86 chairs
Figure number for 86 chairs
= (86 - 2) ÷ 4
= 21
Number of tables for Figure 21 = 21
Answer(s): (a) 4; (b) 42; (c) 21