If I'm not mistaken, then Freebitco use 'round half up' and 'round half down' method for the faucet amount calculation. Therefore, we will receive 1 satoshi from the faucet if $0.002 becomes less than 1.5 satoshi for the price surge of Bitcoin. And the faucet will give 2 satoshi as long as $0.002 stays between 1.5 satoshi to 2.5 satoshi.
- I am just familiar with the method used in Dice (Multiply BTC):
1.5 satoshi rounds to 1 (your "round half down") not like Excel's Round which is 2 (your "round half up")
1.51 rounds to 2 (your "round half up").
Free rolls using rounding to the nearest whole number. Multiply rounds down. It has to do that to avoid being exploitable. If someone bets to win 0.5 Sats and it is rounded up the 100% extra winnings outweighs the 5% house edge.