Length (in meters) snake 1= 0.4 snake 2= 1/5 snake 3= 1/6 snake 4= 0.08 wich one is the longest snake?

To find out which snake is the longest, we need to convert all the measurements into either fractions or decimals. In this case, it's probably easier to compare them all as fractions. But, before doing that, since there are two fractions and two decimals, we can compare the fractions and decimals first, and then compare the two largest numbers. 

0.08 is obviously less than 0.4, because when comparing the tenths place, only 0.4 has a tenth, meaning it is greater.

1/5 is greater greater than 1/6 because it is a greater unit fraction. 

Now, we have to compare 1/5 and 0.4. The easiest way to compare these two is to probably turn them both into decimals. 0.4 is already a decimal, so now we only have to turn 1/5 into a decimal. To make 1/5 a decimal, we just have to preform the division operation, and that gives us that 1/5 as a decimal is 0.2. Since 2<4, that means that the snake that is 0.4 meters is the largest snake.