Get balance

{
    "jsonrpc": "2.0",
    "id": 1,
    "method": "eth_getBalance",
    "params": ["0xaeaa570b50ad00377ff8add27c50a7667c8f1811", "latest"]
}

Get latest block

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_blockNumber"
}

Get block by number

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "eth_getBlockByNumber",
  "params": ["0x1396d66", true]
}