50/60’s sci fi movie using Pi to communicate to aliens

As per 1950's movie includes the line "How about Pi?" (disclaimer: answer mine), possibly Red Planet Mars (1952).

From IMDb:

An American scientist is able to contact and communicate with Mars with shattering political, economic, and spiritual repercussions.

And from the earlier question:

Their kid says "How about Pi?" (the number) while eating a piece of pie, suggesting that the number Pi be used as a code to check if the signals are intelligent by testing if they recognize the sequence of digits and continue it.