NCCER Core Construction Math Fundamentals 2 — Questions and Answers
Question 1: A wall is 12 feet 6 inches long. How many inches is that in total?
- 144 inches
- 150 inches (Correct answer)
- 156 inches
- 126 inches
Correct answer: 150 inches
12 feet x 12 = 144 inches, plus 6 inches = 150 inches total.
Converting between feet and inches: 1 foot = 12 inches, so multiply feet by 12 and add remaining inches. 12 x 12 = 144, then 144 + 6 = 150 inches. This conversion is needed constantly in construction.
Question 2: How many square feet of drywall are needed to cover a wall that is 8 feet high and 14 feet long?
- 96 sq ft
- 112 sq ft (Correct answer)
- 128 sq ft
- 88 sq ft
Correct answer: 112 sq ft
Area = length x height = 14 ft x 8 ft = 112 square feet.
Area = 14 x 8 = 112 square feet. In practice, subtract openings and add 10-15% waste. Drywall sheets are commonly 4' x 8' (32 sq ft each), so this wall needs at least 4 sheets.
Question 3: What is the volume of a concrete footing that is 2 feet wide, 1 foot deep, and 40 feet long?
- 40 cubic feet
- 80 cubic feet (Correct answer)
- 60 cubic feet
- 120 cubic feet
Correct answer: 80 cubic feet
Volume = 40 ft x 2 ft x 1 ft = 80 cubic feet.
Volume = length x width x depth = 40 x 2 x 1 = 80 cubic feet. Convert to cubic yards: 80 / 27 = 2.96 cubic yards. Order approximately 3.25 cubic yards to account for waste.
Question 4: If a roof has a 6:12 pitch, what is the rise for every 12 inches of horizontal run?
- 3 inches
- 6 inches (Correct answer)
- 8 inches
- 12 inches
Correct answer: 6 inches
A 6:12 pitch means the roof rises 6 inches for every 12 inches of horizontal run.
Roof pitch is expressed as rise:run with run always 12 inches. A 6:12 pitch means 6 inches of rise per 12 inches of run. Common pitches range from 4:12 to 12:12, with 12:12 creating a 45-degree angle.
Question 5: Using the Pythagorean theorem, what is the rafter length if the run is 12 feet and the rise is 9 feet?
- 15 feet (Correct answer)
- 18 feet
- 21 feet
- 12 feet
Correct answer: 15 feet
c^2 = 12^2 + 9^2 = 144 + 81 = 225. c = 15 feet.
The Pythagorean theorem (a^2 + b^2 = c^2) finds diagonal distances. Here: 12^2 + 9^2 = 144 + 81 = 225, and sqrt(225) = 15 feet. This is a 3-4-5 triangle multiple (3x3, 4x3, 5x3 = 9, 12, 15).
Question 6: What fraction represents 7/8 reduced to lowest terms?
- 7/8 (Correct answer)
- 3/4
- 14/16
- 15/16
Correct answer: 7/8
7/8 is already in lowest terms because 7 is prime and shares no common factors with 8 other than 1.
A fraction is in lowest terms when numerator and denominator share no common factor other than 1. Since 7 is prime, the only divisors are 1 and 7. Since 7 does not divide 8 evenly, 7/8 is already simplified.
NCCER Core Construction Math Fundamentals 2
A wall is 12 feet 6 inches long.
How many inches is that in total?