Teaching Children How To Weigh Things
Learning How to Measure Weight
Do you know how things are weighed? Three systems of measuring are used throughout most of the modern world -- avoirdupois, Troy, and the apothecarie's systems. Weighing things is an everyday part of life in the US. We weigh our foods, our mail, and many commodities. Do you know the units of measure used for each of these things? Would you use tons, grams, ounces, or pounds? Can you match the following items to the units they are usually measured by?
Grapes
Bananas
Wheat
Sand
Aspirin
An elephant
Steel
Shampoo
Hamburger
The United States uses the avoirdupois system for most weight measurements. In the 1990’s there was a strong push for Americans to switch to metric measures, but US citizens balked at the change. Some changeover has come gradually as Americans learn the measurements. Children know how much a liter of soda pop is. They are learning metric conversion in schools.
The Troy weight system is used for measuring gems and precious metals like gold. Its units are grains, pennyweights, ounce and pounds.
The apothecaries' system was once used to measure all pharmaceuticals (medicines), but now most are measured in metric. Some of the units of this system are grains, scruples, drams, ounce, and pounds.
The weight of any object is the force of the earth’s pull on the mass of the object. Weight is determined by the pull of gravity against the mass or quantity of the item.
Units of Measure
The basic units of weight are different in different countries, according to the system they officially go by. American use these measures.
- Grain
- Dram (equals 27, 34375 grains)
- Ounce (oz.) (equals 16 drams)
- Pounds(lb.) (equals 16 ounces)
- Short ton (equals 2,000 pounds)
- Long Ton (equals 2,240 pounds)
Metric Weight
- miligram (mg)
- centigram (cg) =10 mg
- decigram (dg) =10 cg
- gram (g) =10 dg
- dekagram (dag) =10 g
- hectogram (hg) =10dag
- kilogram (kg) =10 hg
- metric ton (t).=1.000 kg (equals 2,2046pounds)
Weighed in a Balance
Scales weigh things for us. There are many kinds of scales though and you will want to try some of them. Postage scales, kitchen scales, fish scales, balance scales, truck scales used by highway authorities.
Can you weigh things without a scale? You can! Use a balance or comparison methods. A balance has a weight of a set size on one side. You place your object into the other side of the balance until you can get the sides to be level. Ancient Egyptians used this method of weighing heavy things.
You can also estimate the weight of things by comparison. Use an item that you know the weight of, such as a sack of sugar. Estimation is how you know the two things compare. Is your object heavier or lighter than the sack of sugar?
In many professions extreme care is used to weigh items exactly. Many scales are digital and give more precise measurements than were possible to all citizens.
Weighing Project
Grocery scales are for weighing fruits and vegetables. (You will need to go to the grocery store for this one.)
- Weigh one banana on the scale.
- Weigh four onions in the grocery store scale.
- Weigh five apples on the store scale.
- Weigh two avocados on the store scales.
- Write down your measurements.
- Compare to the scales at the checkout.
- Weigh again on bath or kitchen scales at home.
Postage scales may be found in an office. Ask permission to use them.
- Weigh ten sheets of copier paper on a postage scale.
- Weigh today’s mail on a postage scale.
- Weigh a magazine on the postage scale.
- Write down the answers.
- Go to the post office and ask the postmaster to weigh each on his scales to compare.
Bathroom scales are found in most homes.
- Weigh yourself on a bathroom scale.
- Weigh your sister or brother on the bath scale.
- Weigh your pet on the bathroom scales.
- Weigh a friend on the scale. Write down all the weights.
- Now try with a digital scale.
A fshing scale can be purchased in sporting section of Wal-Mart.
- Weigh a shoe or boot on a fish scale.
- Weigh a purse on the scale.
- Weigh a toy on the fish scale.
- Weigh a coffee mug on the scale.
- Weigh a fish on the fish scale.
- Write down the weight of each item.
- Weigh each again on the bathroom scale and compare.
The skill of weighing items and learning the basic weights used is important. It is also interesting to note how weights and measures differ in various countries. Weighing items can be of great interest and help you develop the ability of estimating weights which will come in handy many times. How much do you weigh? How much would you weigh on the moon?
Tomato on Scale
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