# Carpentry & Building Construction

## Math Activities :

### Converting Square Units

Building materials have different unit specs. Some materials are measured in square inches and others in square feet or yards. Flooring materials, such a vinyl or ceramic tiles, may be available by the square foot. Carpeting is typically ordered by the square yard. Some sheet materials are measured by the square inch. Carpenters may have to convert from one square unit to another.

• sq. in. ÷ 144 = sq. ft.
• sq. ft. × 144 = sq. in.
• sq. yd. × 9 = sq. ft.
• sq. ft. ÷ 9 = sq. yd.
 Terms, Symbols, & Abbreviationssquare unit = measure of the area of a surfacesq. ft. = square inch, or square inchessq. ft. = square foot, or square feetsq. yd. = square yard, or square yards

Practice Exercises

Convert 2 1/2 sq. ft. to square inches.

 Step 1 2 1/2 = 2.5 Step 2 sq. ft. × 144 = sq. in. Step 3 2.5 × 144 = 360 sq. in.

Convert 432 sq. in. to square feet.

 Step 1 sq. in. ÷ 144 = sq. ft. Step 2 432 ÷ 144 = 3 sq. ft.

Convert 5 sq. yd. to square feet.

 Step 1 sq. yd. × 9 = sq. ft. Step 2 5 × 9 = 45 sq. ft.

Convert 16 sq. ft. into square yards, rounding to the nearest hundredth.

 Step 1 sq. ft. ÷ 9 = sq. yd. Step 2 16 ÷ 9 = 1.78 sq. yd.

Problem Exercises

 1 A contractor must order flooring materials by the square yard for a 12' × 15' kitchen. The order will be for A) 20 sq. yd. B) 40 sq. yd. C) 90 sq. yd. D) 180 sq. yd. 2 A remodeling job requires replacing 17 square yards of carpet. How much would this be in square feet? A) 51 B) 76.5 C) 153 D) 306 3 There are 936 sq. in. of sheathing to be replaced, or ______ sq. ft. A) 6.5 B) 9 C) 65.5 D) 78 4 You have a 200 sq. ft. roll of plastic drop sheeting, or ______ square inches. A) 2,400 B) 12,000 C) 14,400 D) 28,800 5 A wall coating covers 352 sq. ft. of wall area or about ______ square yards. A) 2.44 B) 4.88 C) 29.33 D) 39.11