Rule # 1.
To find 36 on the divisions of 2/3, first divide the given number by 2 or 36/2 equals 18. Use the quotient (18) as the scale. Locate it in the division of 2/3 and refer to the other side/back of the square for the answer in inches as 2/3 of 1/2 of 36 inches is equals 12 inches.
Use the same scale (18) for the same number 36 in 1/3 division, 1/3 of 1/2 of 36 inches equals 6 inches. In 1/6 division, 1/6 of 1/2 of 36 inches equals 3 inches.
Rule # 2.
To compute 36 on the division of 1/2, first divide the number by 2 or 36/2 equals 18. Use the quotient (18) as the scale. Locate it in the division of 1/2 (halves) and refer to the other side/back of the square for the answer in inches as 1/2 of 1/2 of 36 inches is 9 inches.
Use the same scale (18) for the same number 36 in 1/4 division thus: 1/4 of 1/2 of 36 inches is 4 1/2 inches.
Rule # 3.
For numbers (measurement) below 24, do not divide the number by 2. Locate the number ex. 22 below the division mentioned.
Ex. 23, 22, 21, 20, 19, 18 etc.
In 1/2 division, 1/2 of 1/2 of 22 inches. The division mentioned here is 1/2 division, since the number/measurement is below 24 do not divide the number by 2. Locate the exact number 22 on the division of 1/4. This 1/4 division is located below the division of 1/2.
REFERENCE:
Rondilla, et.,al (2000) Technology and Home Economics III, (Experimental ed.) Adriana publishing.