Infant raised to do simple arithmetic (3,2)

I believe the answer is:

tot up

'to do simple arithmetic' is the definition.

'infant raised' is the wordplay.
'infant' becomes 'tot' (tot means a young child).
'raised' becomes 'up' (similar in meaning).
'tot'+'up'='TOT UP'

(Other definitions for tot up that I've seen before include "Add together (driving offences)" , "Add (some numbers)" , "Do summer job" , "Tally" , "Count" .)

I've seen this clue in The Globe and Mail and The Sun.

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