1 Two labels have been omitted in the mathematics below. Where should they go to make sense of the argument?

• Since

Author(s): The Open University

Sometimes you may want to refer to mathematical sentences or phrases further up your work. You can label such sentences and then refer back by label. Thus, Example 3 could be laid out as follows.

So, from (1) and (2),

Author(s): The Open University

1 In the following two pieces of mathematical writing, remove or replace any inappropriate equals signs, and add link words and punctuation to help somebody else understand the mathematics.

• (a)

Author(s): The Open University

A lot of people use the equals sign wrongly in places where another word or phrase might actually make the meaning clearer. Sometimes a link word or phrase is useful at the beginning of a mathematical sentence: examples include â€˜Soâ€™, â€˜This impliesâ€™ or â€˜It follows thatâ€™ or â€˜Henceâ€™.

## Example 3

Author(s): The Open University

1 Here is a poor example of mathematical writing, although the final answer is correct. Rewrite it, correcting the layout and the mathematical punctuation.

Author(s): The Open University

As mentioned previously, one of the most misused mathematical symbols is the equals sign, =. It stands for the verb â€˜equalsâ€™ or the phrase â€˜is equal toâ€™ or â€˜which equalsâ€™, and so it should only come between two things that are equal.

## Example 2

Which of the equals signs should not be
Author(s): The Open University

1 Read the following expression out aloud or write it out in full in words:

• (a) 21 + 34 = 55

Author(s): The Open University

As mentioned in the animation in Section 1.2 writing mathematics has a lot in common with writing English. When you write mathematics, you should write in the equivalent of sentences, with full stops at the end. As in English, each new statement should follow on logically from the previous one or it should contain an indication that a new idea is being introduced. However, laying out mathematics differs from laying out English: because mathematics is more condensed than written English
Author(s): The Open University

One way of testing whether or not you are conforming to the first guideline, is to read your solutions through aloud. Speaking aloud involves you in translating every symbol on the page into its verbal equivalent. If you find yourself needing to say more than is written on the page, you may need to expand your written account. To give you practice at this and at assessing the quality of some written mathematics, work through the animation below. The actual mathematics used is not important; j
Author(s): The Open University

Except for third party materials and otherwise stated (see terms and conditions), this content is made available under a Creative Commons Attribution-NonCommercial-ShareAlike 2.0 Licence

Grateful acknowledgement is made to the following sources for permission to reproduce material within this product.

## Author(s): The Open UniversityLicense informationRelated contentExcept for third party materials and/or otherwise stated (see terms and conditions) the content in OpenLearn is released for use under the terms of the Creative Commons Attribution-NonCommercial-Share

Timetables and distance-time graphs are different representations of scheduled train movements. They are both models which can be used to predict when trains will run, to analyse and compare different schedules when problems occur, and to design new operating schedules to meet new demands. Both models provide information which allows the company to operate safely and flexibly. The information is used by different groups of people:

• Author(s): The Open University

Now watch the video.

Video, Click to watch part three