Note that the numbers get bigger as you go down the buret. This is different from the beaker or the graduated cylinder. This is because the liquid leaves the buret at the bottom. The number of significant figures is directly linked to a measurement. Leading zeros are never significant.
Imbedded zeros are always significant.
Trailing zeros are significant only if the decimal point is specified. Change the number to scientific notation. It is easier to see. The last digit retained is set by the first doubtful digit. The answer contains no more significant figures than the least accurately known number.