A = 5 significant numbers
B= 3 significant numbers
C = 5 significant numbers
D = 4 significant numbers
E. = 6 significant numbers.
significant numbers are values that have been measured.
Numbers or digits that result from calculations are not scientifically significant.
A. All five digits are significant, because they are exact number that are written as though the digits are measured.
b. All three digits are significant ( same as above.)
C. All five digits are significant. The two zeros at the end are significant. There is no mathematical reason for writing them, they are not place holders so they are significant.
D. All four digits are significant The one zero to the right of the decimal point is significant. ( see answer above.)
E. All six digits are significant. The zero to the right of the decimal point is significant because a zero in the tenths place is a precise measured value because there is a value in the hundredths place.
The zero to the right of the nine is significant ( see answer part C)