B0: < 5

B1: 5 to 10

B2: 10 to 15

B3: 15 to 20

B4: 20 to 25

B5: > 25

Notice that

floor( 2 / 5) = 0, so put 2 into B0

floor( 5 / 5) = 1, so put 5 into B1

floor( 6 / 5) = 1, so put 6 into B1

floor(18 / 5) = 3, so put 18 into B3

floor : Returns the largest integer less than or equal to the specified decimal number.

Not sure is this is what you had in mind. I'll be back tomorrow.

B1: 5 to 10

B2: 10 to 15

B3: 15 to 20

B4: 20 to 25

B5: > 25

Notice that

floor( 2 / 5) = 0, so put 2 into B0

floor( 5 / 5) = 1, so put 5 into B1

floor( 6 / 5) = 1, so put 6 into B1

floor(18 / 5) = 3, so put 18 into B3

floor : Returns the largest integer less than or equal to the specified decimal number.

Not sure is this is what you had in mind. I'll be back tomorrow.