Last time, I explained why#BTCis halved every four years. Today, let's talk about why the total amount of BTC is 21 million. In fact, this is a simple math problem. BTC generates a block approximately every 10 minutes (this 10-minute setting should be a technical consideration. If the block is produced too quickly, the consumption will be too high, because for each block, all mining machines have to perform a large number of hash operations. If the block is produced too slowly, it may affect the efficiency of the Bitcoin network). The time for 210,000 blocks is 1458 days and 8 hours, which is about 4 years. Initially, each blockchain rewarded 50 BTC, and the reward was halved every 210,000 blocks, so the total output of the Bitcoin network is equal to 50*210000+25*210000+12.5*210000+…… The limit of the geometric sequence is equal to (50*210000)/(1-0.5)=21 million. In EXCEL, you can list the data and draw charts. In the output chart, we can see that BTC output is a nearly closed graph, and the area of ​​21 million is not very obvious. The following BTC total amount chart is very obvious, infinitely close to 21 million. The mathematical beauty of BTC!