Own and Bella shared 1 granola bar. Bella ate 1/4 of the bar, Owen ate 1/3 of the bar. Which would be the correct next step to calculate how much of the granola bar is left?

1-1/4-1/3=1-2/7
1-1/4+1/3=1-3/12+4/12
1-1/4-1/3=1-3/12-4/12
1+1/4+1/3=1+2/7

The correct next step to calculate how much of the granola bar is left would be 1 - 1/4 - 1/3 = 1 - 2/7.