They help calculate some playground regulations? (5,5)

I believe the answer is:

slide rules

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'they help calculate some' is the definition.
The definition suggests an adverb but the answer is not.

'playground regulations?' is the wordplay.
'playground' becomes 'slide' (I can't explain this - if you can you should give a lot more credence to this answer).
'regulations?' becomes 'rules' ('rule' can be a synonym of 'regulation').
'slide'+'rules'='SLIDE-RULES'

Can you help me to learn more?

I've seen this clue in The Guardian.

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