Firstly, conversion of reinforcement area for flexural (longitudial) beam reinforcement to 'number of bars' is similar to that for the vertical reinforcement of columns. However, for deciding the 'number of bars provided' in case of beams, we round the calculated value to next higher integer number only, whether it is even or odd. For example, if required steel area is 0.9 sq.in., and #5 bar is to be used, then required number of bars =0.9/0.307=2.93. In this case, we may use 3 #5 bars for the beam. (Whereas, in case of a square or rectangular column, we needed to use at least 4 bars.)
Secondly, in case of a beam, required number of bars are to be provided along the relevant (top or bottom) face of the beam only, depending upon whether we are detailing the reinforcement for the negative or positive bending moment. In case, required number of bars (as calculated in previous paragraph) exceeds the maximum number of bars permissible in one layer, required number of bars will be provided in layers, separated vertically by spacers.
Thirdly, total area of reinforcement provided, must be within the steel areas corresponding to Minimum & Maximum steel ratios prescribed by ACI 318 for the beams.
Fourthly, detailing of all type of beam reinforcement needs be in accordance with relevant provisions of ACI 318 and ACI 315 (whether seismic or non-seismic, as applicable).
Out of three reinforcement values shown along (the top or bottom side of) a beam, two outer values (0.9 & 0.9 at left & right sides of top face, and 0.6 & 0.4 at left & right sides of bottom face of the beam under discussion) indicate the amount of reinforcing steel required at the relevant (top & bottom) faces of the two supports. Whereas, the middle values (0.2 on the top, & the 0.6 on the bottom side) indicate the amount of reinforcing steel required at the mispan of the beam, on the top & bottom faces respectively.
HTH
Regards.