Three sections work the same skill in three different notations. Part A gives twelve problems written left to right with a line for the answer, Part B sets six of them in the long division bracket, and Part C turns six into missing number sentences where the dividend or the divisor is the blank.
The middle section is the one that earns the page. A child meets the long division bracket for the first time around this stage, and meeting it here, with facts they have already practiced and quotients that come out clean, means the notation is the only new thing to deal with. Part C then asks them to work backwards, which is where you find out whether division is understood or just recognized.