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Technology

Grade 5

Graphic communication

Module 4

Measuring systems

The development of measuring systems

Background:

Since the earliest times measuring was one of man’s most important activities, but in those days no accurate measuring-instruments existed. Parts of the human body were used as measuring-instruments and these later became the measuring-units. As technology developed, and people gradually became more civilised, measuring-instruments and measuring-units became more accurate.

What is measuring:

Measuring is the process of comparing that which we want to measure with the unit with which we measure.

The Romans standardised and safeguarded the Babylonian measuring-systems in ± 600 B.C., and these systems were used throughout the entire civilised world of that time.

The Roman measuring system:

1 foot = 16 fingers’ breadth = 12 inches

1 ½ foot = 1 ell

2 ½ foot = 1 step

5 foot = 1 double step

1 000 double steps = 1 mile

4 fingers’ breadth = 1 hand breadth

3 hands’ breadth = 1 span

2 span = 1 ell

ASSIGNMENT 1:

[lo 3.2]

What problem was caused by the fact that people of an earlier civilisation used their limbs as measuring-instruments?

Measures and Weights

In Biblical times people used different measures and weights from those that are used today. Try to use their measures.

a) A finger’s breadth is the breadth of a finger.

b) A hand’s breadth is measured below the fingers.

c) A span is measured right across an outstretched hand.

d) An ell is the length from the elbow to the tips of the fingers.

ASSIGNMENT 2: [lo 3.1]

In old translations of the Bible we read that Goliath was six ell and a span. According to the scale one ell = two span, thus Goliath was __ span tall. Measure this out and then measure the length with a measuring-tape. How does his length compare with your own length?

(Copy and complete)

His length:

My length:

Difference:

According to the new translations of the Bible Goliath was

__ m tall (see 1 Sam. 17:4).

Is there a marked difference?

If there is, give a reason for this difference.

ASSIGNMENT 3:

[lo 3.2]

Something interesting: Noah’s ark was 300 ell long.

Measure the ell (from the point of the middle finger to the elbow) of three teachers at your school. Copy the table and complete:

Name of Teacher ELL in mm
1
2
3
Average ELL

Calculate the length of the ark in mm

At break time, measure it out on your playing field. According to Gen. 6:15 the ark was 135 m long.

Does your answer agree with that?

If not, why would it differ?

Background:

In 1834 the English kings made it their mission to develop a uniform measuring-system that could be used throughout the whole world, because each country in Europe had its own system. The metric system came into being as a result of the work of brilliant French scientists and mathematicians who developed a new decimal measuring-system in 1795. A fixed length was allocated to a specific unit and this resulted in the fact that from then on measurements were reliable. By the end of the 19 th century 22 countries were already using the metric system.

Certain measuring-instruments were designed and this made the job of measuring things much easier. Some of these instruments are the tape-measure, the precision measuring wheel, the metre-stick and the ruler.

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Source:  OpenStax, Technology grade 5. OpenStax CNX. Sep 23, 2009 Download for free at http://cnx.org/content/col10979/1.2
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