In the model shown, the blocks are divided into hundredths.
The completely shaded block represents the whole number 1. There are two partially shaded blocks. One block shows 42 hundredths shaded, and the other block shows 56 hundredths shaded.
To subtract, regroup one of the completely shaded blocks into hundredths and combine it with 42 hundredths.
142 hundredths - 56 hundredths = 86 hundredths.
As one of the wholes was regrouped to subtract, only one whole block remains. Combine that 1 whole with 86 hundredths to get 1.86.
So, the model shows that 2.42 - 0.56 = 1.86.