Largest practical science lesson (multiple venues)

According to Official Guinness Records,

The largest practical science lesson at multiple venues involved 13,701 participants and was achieved by Science.gc.ca (Canada) at 88 locations across Canada, on 12 October 2012.
All lessons began at 1 pm EST and included 2 experiments which demonstrated Bernoulli's Principle on air pressure.

For a complete list of 2012 records, please visit 2012 Guinness Records in Canada.

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