Sample: Addresses on a Centimeter Scale Ruler

1. Draw a horizontal line segment of length 10 cm. Mark the endpoints with vertical segments of length 1 cm.
2. Divide the horizontal segment into pieces of length 1 cm. Mark thee segments with vertical segments of length 0.5 cm.
Assign an address 0 to the leftmost tenth, 1 to the next tenth, 2 to the next tenth, ..., 9 to the right tenth.
Note the address of each interval is the number of tenths of all points in that interval.
3. Divide the horizontal segment into pieces of length 0.1 cm. Mark thee segments with vertical segments of length 0.25 cm.
To the subdivisions of the interval with address 0 assign addresses 00, 01, ... , 09; to the subdivisions of the interval with address 1 assign addresses 10, 11, ... , 19; and so on.
Note the address of each interval is the number of hundredths of all points in that interval.
4. To relate this to the more familiar notion of addresses through IFS, the subdivision of 2. can be achieved through these functions.
f0(x) = x/10 + 0/10 f1(x) = x/10 + 1/10
f2(x) = x/10 + 2/10 f3(x) = x/10 + 3/10
f4(x) = x/10 + 4/10 f5(x) = x/10 + 5/10
f6(x) = x/10 + 6/10 f7(x) = x/10 + 7/10
f8(x) = x/10 + 8/10 f9(x) = x/10 + 9/10
Thinking of the original interval of 1. as [0, 1], the region with address 37 is f3(f7([0,1])).

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