Step-by-step explanation:
the positions right of the decimal point have the unit values :
tenths
hundredths
thousandths
ten-thousandths
hundred-thousandths
millionths
...
let's count : hundred-thousandths is the 5th position to the right of the decimal point.
so, the 6th position (in our case 8) determines the rounding of the 5th position (in our case 7 rounded up to 8).
or rounded number is therefore
2.43518