Im having trouble cancelling out the numbers and letters! : ) you

First change the devision to multiplication 
second see the common letters and cross them

You could buy 276 single markers, you can buy 28 packs of markers, or 3 boxes of marker because 1pack = 10 markers, 10 markers multiplied by 10 packs equals 100. So 1 box would have 100 markers in it and if you took 2 boxes you would be missing 76 markers, so you're better off getting 3 boxes and having 300 markers than being less by 76.