How can you tell which decimal is bigger? Subtract one from the other and see if the result is positive or negative. If the decimal point bothers you, move it to the right the same number of places (2 in this case) in both numbers till it falls off the edge and becomes invisible. Then you can see which number is bigger. If we do that with these numbers we get 1342 and 1309. 1342 is bigger because we can subtract 1309 from it and have 33 remaining. So 13.42 is bigger than 13.09. Subtracting 13.09 from 13.42 would give us 0.33 (replacing the decimal point).