According to the rules for significant figures: (1) In $0.007$, the leading zeros are not significant; only the '7' is significant (1 figure). (2) In scientific notation $2.64 \times 10^{24}$, only the base number $2.64$ counts; the power of 10 is irrelevant for significance (3 figures). (3) In $0.2370$, the leading zero is not significant, but the trailing zero after the decimal point is significant (4 figures). Hence, the counts are 1, 3, and 4.