How many Bitcoin are mined per day? A block is generated every ten minutes. The reward changes periodically, and will halve 32 more times. What is the approximately daily reward across the entire network?
All times approximate.

Each block takes ten minutes, so there are six blocks per hour, 24 hours per day. The original block reward was 50 BTC. Thus, 7200 BTC per day introduced to the system.

I contrived this script to model the decline, including the year the halving is expected to occur: 

ruby -e 'reward = 7200.0; halving = 0; while halving &lt; 33 do puts "Halving "+halving.to_s + " (" + (2008 + 4 * halving).to_s + ") : %2.8f"%reward; reward = reward / 2; halving += 1; end'

Start (2009) : 7200.00000000 #start
Halving 1 (2012) : 3600.00000000 #Halving was November 2012
Halving 2 (2016) : 1800.00000000
Halving 3 (2020) : 900.00000000
Halving 4 (2024) : 450.00000000
Halving 5 (2028) : 225.00000000
Halving 6 (2032) : 112.50000000
Halving 7 (2036) : 56.25000000
Halving 8 (2040) : 28.12500000
Halving 9 (2044) : 14.06250000
Halving 10 (2048) : 7.03125000
Halving 11 (2052) : 3.51562500
Halving 12 (2056) : 1.75781250
Halving 13 (2060) : 0.87890625
Halving 14 (2064) : 0.43945312
Halving 15 (2068) : 0.21972656
Halving 16 (2072) : 0.10986328
Halving 17 (2076) : 0.05493164
Halving 18 (2080) : 0.02746582
Halving 19 (2084) : 0.01373291
Halving 20 (2088) : 0.00686646
Halving 21 (2092) : 0.00343323
Halving 22 (2096) : 0.00171661
Halving 23 (2100) : 0.00085831
Halving 24 (2104) : 0.00042915
Halving 25 (2108) : 0.00021458
Halving 26 (2112) : 0.00010729
Halving 27 (2116) : 0.00005364
Halving 28 (2120) : 0.00002682
Halving 29 (2124) : 0.00001341
Halving 30 (2128) : 0.00000671
Halving 31 (2132) : 0.00000335
Halving 32 (2136) : 0.00000168


(I did modify the output a little to make it easier to understand without complicating my script)