Presentation on theme: ""How heavy is it?""— Presentation transcript:
"How heavy is it?" http://www.coe.uh.edu/archive/science/science_lessons/scienceles3/
History The Babylonians' unit of weight was the ka and the gur. The gur equaled to about 80 gallons. These were the earliest known units given for weight. The Hebrews' units were the bat, log, and the hin. Like the customary system, the Hebrews had units to measure both dry and wet substances. Inherited by Medieval Europe, the Roman system developed the pinte to measure liquid and the quart to measure dry substances. The US still used "Queen Anne's gallon," which was discarded from the British in 1824 until they later adopted the bushel. The bushel was also derived by the British and was called,"Winchester bushel." The relationship between these two units (the gallon and the bushel) are almost equivalent.
Units of Weight The common units for measuring weight in the customary system are ounces, pounds, and tons. A serving of dry cereal weighs about one ounce. A loaf of bread is about a pound. A compact car weighs about a ton. From smallest to greatest they range: Ounces Pound Ton
Reading a Scale Scales at the grocery stores show weight in pounds and fractions of a pound which include: halves, fourths, eighths, and sixteenths. Reading a scale marked with pounds and fractions of a pound is similar to reading a ruler. The only difference is that a scale has the geometric shape of a circle. When reading the scale, find the nearest whole pound before the arrow shown on the scale. Then find the fraction of a pound that the arrow is pointing to. The total amount is read as a fraction if it is under a pound, exactly a pound, or a mixed fraction if it is over a pound.
A shows 9/16 pound. D shows 2 1/2 pounds. B shows 1 pound. E shows 3 1/16 pounds. C shows 1 3/4 pounds. F shows 3 5/8 pounds.
Conversion Chart MEASURES OF WEIGHT 1 pound (lb.)=16 ounces (oz.) 1 ton (T.)=2,000 pounds (lb.) When converting any unit of measurements if you want: To change to a larger unit, divide. To change to a smaller unit, multiply.
Drill and Practice 1. The weight of a hamburger is 4 ounces 4 pounds 2. The weight of a golfball is 4 ounces 4 pounds 3. The weight of a truckload of steel is 7 pounds 7 tons 4. The weight of a ambulance is 4,000 pounds 4,000 tons 5. The weight of a bag of potatoes is 5 ounces 5 pounds