Search results
Results From The WOW.Com Content Network
For degrees, percentage (%) and per-mille (‰) notations, larger numbers are steeper slopes. For ratios, larger numbers n of 1 in n are shallower, easier slopes. The examples show round numbers in one or more of the notations and some documented and reasonably well known instances.
Decimal fractions were first developed and used by the Chinese in the form of rod calculus in the 1st century BC, and then spread to the rest of the world. [6] [7] J. Lennart Berggren notes that positional decimal fractions were first used in the Arab by mathematician Abu'l-Hasan al-Uqlidisi as early as the 10th century. [8]
Definitions vary on when a roof is considered pitched. In degrees, 10° (2 in 12 or 1 in 6) is considered by at least one reference a minimum. [5] In trigonometric expression, exact roof slope in degrees is given by the arctangent. For example: arctan(3 ⁄ 12) = 14.0°. Framing carpenters cut rafters on an angle to "pitch" a roof.
Subdivisions of an inch are typically written using dyadic fractions with odd number numerators; for example, two and three-eighths of an inch would be written as 2 + 3 / 8 ″ and not as 2.375″ nor as 2 + 6 / 16 ″. However, for engineering purposes fractions are commonly given to three or four places of decimals and have been ...
An irreducible fraction (or fraction in lowest terms, simplest form or reduced fraction) is a fraction in which the numerator and denominator are integers that have no other common divisors than 1 (and −1, when negative numbers are considered). [1]
It is denoted by a single prime ( ′ ). For example, 3° 30′ is equal to 3 × 60 + 30 = 210 minutes or 3 + 30 / 60 = 3.5 degrees. A mixed format with decimal fractions is sometimes used, e.g., 3° 5.72′ = 3 + 5.72 / 60 degrees. A nautical mile was historically defined as an arcminute along a great circle of the Earth.
Example (inch, coarse): For size 7 ⁄ 16 (this is the diameter of the intended screw in fraction form)-14 (this is the number of threads per inch; 14 is considered coarse), 0.437 in × 0.85 = 0.371 in. Therefore, a size 7 ⁄ 16 screw (7 ⁄ 16 ≈ 0.437) with 14 threads per inch (coarse) needs a tap drill with a diameter of about 0.371 inches.
In primary education, fractions of grades are identified with a + or −, which signifies a quarter (converted to either 0.8 or 0.3 if only one decimal place is used). Thus, a grade of 6.75 (or 6.8) could be written as 7−, whereas a grade of 7+ would count for 7.25 or 7.3. A 5.5 constitutes a pass, whereas 5.4 and below constitute a fail.