Which has the smallest value 11 , 0.675,1.23,0.42,1.011

The number with the smallest value is 0.42.

Here are the numbers listed in order from least to greatest.

0.42, 0.675, 1.011, 1.23, 11

The reason has to do with the values of the position of the numbers. All Numbers to the left of the decimal point are whole numbers. Any number with numbers to the left have a whole number which is bigger than any decimal.

To the right of the decimal point the place values gets smaller the further you are to the right.

Compare 0.42 and 0.675
The 4 and 6 are both in the tenths place, therefore 0.42 is the smallest no matter how many more digits either has to the right of that number.