5.3 Numbers

How do I express numbers in my writing?

When is it necessary to write numbers as numerals (1, 2, 3, 4 …) or as words (one, two, three, four, …)? The answer is always to present your work as clearly as possible. Is your text unreadable because of an overloading of numerals or, in contrast, are some important figures unnecessarily hidden within the text?

The following are some general rules which should be followed, including correct examples:
􀂃 Numerals should not be used at the beginning of a sentence.
One of the specimens underwent fatigue testing.
Four aircraft wings failed under loading.

􀂃 Numerals should not be used in succession or in a series of numerical facts.
eighty 5mm rivets
3 two-stroke engines

􀂃 Numerals should not be used for round number estimates or ordinals.
 the second report dealt with fractures due to stress
 approximately two hundred cracks were observed

􀂃 Use numerals for all page numbers, dates, figures, diagrams, addresses.

􀂃 For numbers below ten, words tend to be preferred to numerals.

5.4 Passive Voice

The passive voice is frequently used in technical and scientific writing because the form is impersonal and objective. The action is felt to be more important than the agent or the performer of the action.

action
The survey was conducted

agent
by the Pristop Communication group.

What types of passive construction are there?

with an agent stated
To avoid tensile stress reflecting from the free boundaries, a star-shaped flyer plate has been proposed by Kumar and Clifton.

without an agent stated
The distance between the bars was measured.

Which are the most common passive tenses used in technical and scientific writing?

􀂃 Present passive. We normally use the present passive tense when describing a process or procedure or when making general statements of fact.
Paper is made from wood.
The trees are cut down.

􀂃 Past passive. When we report a particular procedure and are concerned with only one particular occasion in the past; then we use the past passive tense.
The capillary was filled with mercury and all air excluded. Air was admitted to the chamber and heated.

􀂃 Present perfect passive. This tense is often used in the introduction where you might want to refer to things relating to your work that have happened, or been said, recently.
For example, it has been suggested that cathepsin S promotes motility of cilia. On the other hand, the possibilities of computational modelling have increased in the last few years, enabling the models to be much more realistic.

􀂃 Passive with modals. These are commonly found in technical and scientific writing in such phrases as
It should be made clear that …
It cannot be assumed that …

Points to check in your writing

􀂃 the passive forms is placed on / given to / by are preferable in English to the active
During the last two years of study, increasing emphasis is placed on practical training.
Figure 6 in the previous section shows that, for the Lorenz system, better results are given by quadratic than linear functions.

􀂃 using passive constructions is one way of avoiding the first person singular in technical or scientific writing
It can be concluded that …

􀂃 In long sentences active constructions are better because the verb in passive constructions could come at the end of the sentence, which makes a construction clumsy.

passive
For this reason, the emission and excitation spectra of Hg2CL2 luminescence on virgin samples and samples exposed to UV light and X-ray were studied.

active
For this reason, the subject of the study was the emission and excitation spectra of…

􀂃 Overuse of the passive should be avoided. Variation between active and passive verb forms keeps the reader more interested.

In domestic trade, more than 50% actual sales are derived from wood and building materials, while the rest comes from furnishing materials for buildings and engineering services.