Aa batteries come in  packs of 4. last month, joe used 58 batteries in his remote control drone. how many  packs  of batteries did he have to open?  

Batteries come in a pack of 4.

This means

Number of batteries in each pack = 4.

Number of batteries Joe used last month for his remote controlled drone  = 58.

Number of packets he needs to open = 58/4 = 14.5

But you cannot open half a packet.

So the number of packets we need to open to use 58 batteries is 15.