I've noticed since I start Factorio in 0.12.29 that research actually takes a minuscule amount more than they claim they require.
Depending on how close biter nests are my first research is turrets then automation or visa-versa. Both of these need 10 science packs to research. So that is 20 science packs total. However I find myself always needing 21 science packs to research both of them.
- Start a new game.
- build 1x water pump, 2x boiler, 3x steam engine, 1x science lab, 20x red science and however small power poles you need.
- Shove all 20 science packs into the one lab.
- Research Turrets
- Research Automation
- Find yourself short by a tiny smidgen.
- Craft one more red science and toss it into the lab.
- Research instantly finished and science pack is 99% remaining.
Seems like there is some kind of round error somewhere?