Two.
4
1 metre = 1000 millimetres so 00019 metres = 19 metres = 1000*19 = 19000 millimetres. Simple!
It has two significant digits.
It has 3 significant digits.
3 significant digits.
Five. All nonzero digits are significant and zeros in between significant digits are significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
Five. All nonzero digits are significant and zeros in between significant digits are always significant.
50.4 has 3 significant digits.
There are 4 significant digits in 5600.
This number has seven significant digits.