Wiktionary
number crunching
n. (alternative spelling of number-crunching English)
WordNet
number crunching
n. performing complex and lengthy numerical calculations
Usage examples of "number crunching".
His Excellency always appreciates a creative bit of number crunching.
The problem of interference with the after beta nodes would require some careful number crunching, but it was the matter of power supply which seemed likely to pose the real difficulties.