The Central Bank of Nigeria (CBN) is limiting cash withdrawals for individuals to N100k ($225) and N500k ($1,325) for businesses.
That is the withdrawal limit per-week, expressed in dollars, using the "official" exchange rate of N445 per USD (i.e., N100,000 / 445 = $225).
But take N100,000 to a Bureau de Change / foreign currency conversion dealer and you will pay the USD/NGN "parallel market rate", of about N740 per USD ... getting you only $135. In other words, your purchasing power from cash withdrawals is about $135 per week, or ~$19 per day.