Chang's Math blog

Well-intended Advice:

● For True statements, circle the facts from your observation or calculation to justify the truth

● For False statements, circle the untrue number, word or phrase in the statement and

○ write the “correction” or “OTB” (ought to be”) that would correct the false statement to true.

○ Cite numerical inconsistencies that doomed the statement to be untrue. (eg. when certain numbers have to be odd, or say multiples of 3 etc, as dictated by certain ratios as stated in the question, and yet are inconsistent)

● For Not Possible to Tell (NPTT) statements, circle the ambiguous word/clause and cite other possibilities to satisfy the claim of the statement.*

* Usually statements are deemed NPTT when the numerical quality is consistent, but there exist more than one possibility ie. “spoilt for choices”.