7 21 77 are moving averages. Moving averages are nothing more than a line that averages price movement over a set amount of periods. So a 7 is the average price over 7 periods relative to time frame. So if I am looking at a 5 minute chart the 7 is representative of 35 minutes, whereas if I am looking at the 1 hour it represents 7 hours. It moves quickly as it gets its average from a shorter span of time. The 21 would be average price over 21 periods, and 77 would be average price over 77 periods.

To give you a better idea go here: https://cryptowat.ch/bitfinex/btcusd/15m

That is a free charting service, in the upper right hand corner are tools. Go to SMA (simple moving average) and select your time frames.

This may also help..

https://www.investopedia.com/terms/m/movingaverage.asp

Here is good as well:

http://etfdb.com/etf-trading-strategies/3-simple-moving-average-etf-trading-strategies/

In the last article a 10/30 would be a 7/21 for me. If you have any questions feel free to ask. Also fantasy trading is great as there is no emotion, you can trade like a bot, because there is no fear of loss. The trick is to have that same emotional detachment when real money is on the line. Kinda like being with a girl that's fun to (netflix and chill with) but your not going to be upset if she never calls again- emotionally detached..