John Dixon, independent medical writer and trainer in scientific writing skills, provides a useful tip for medical writers who work in MedComms.

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Recorded 25 March 2019. Produced by

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Hi, I’m John Dixon, a trainer in scientific writing, and here’s a bite that I hope may help you with your writing.
Writing numbers [NEXT SLIDE]

Whilst style guides can vary, here are the usual rules about writing numbers.
For cardinal numbers zero to nine, write them out in full …pause…
For cardinal numbers 10 and above, write out the numeral …pause…
For ordinal numbers – that is, numbers indicating position in a sequence – the rule is the same …pause… [NEXT SLIDE]

However, spell out a number if it begins a sentence …pause…
Better still, to avoid clumsiness and for clarity, it’s often better to rewrite a sentence to avoid a number at the beginning
So – one thousand two hundred and fifty-three patients entered the trial – is better written as –
A total of 1,253 patients entered the trial – and write the large number as a numeral. [NEXT SLIDE]

Use numerals with SI and SI-derived units …pause…
Place a space between a numeral and unit – including degrees Celsius – as shown in the examples above, except with measures of angle:
So 36 degrees, 7 minutes and 23 seconds of angle have no space between numeral and unit
There’s no universal agreement on placing a space between a number and the % sign …pause… :
These examples may all be correct, depending on the style guide. Some argue that a half space looks best between a number and the % sign.
But follow your style guide (if you have one) and in any case make sure you’re consistent throughout your document. [NEXT SLIDE]

When two or more numbers in a sentence or passage describe the same collective, use numerals for clarity, even if one number is less than 10 …..long pause..… [NEXT SLIDE]

When two numbers are adjacent, write out the number most easily conveyed in words to make reading easier: …pause…
But – usually keep a numeral that occurs with a unit of measurement …pause… [NEXT SLIDE]

Finally, be consistent with commas separating thousands, and using a zero before the decimal point …pause…
These examples may all be correct, but – again – follow your style guide if you have one – and in any case be consistent throughout your document.

I hope that’s helpful. For more bites to help your writing, visit

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