Okay, so imagine you have a number that's really big, like a million. Now imagine breaking up that big number into smaller parts, so it's easier to understand.
The number 1025 is like that too. It's made up of two different parts: 1,000 and 25. The first part (1,000) is a special number because it has three zeros. This means it's ten times bigger than 100, which has two zeros, and a hundred times bigger than 10, which has only one zero.
The second part, 25, is just a regular number. It's smaller than 100, which means it's less than ten times bigger than 10.
When you put these two parts together, you get the number 1025. It's bigger than 1000, but not by too much because the second part (25) is relatively small compared to the first part (1,000).
So if you hear someone say "1025 riema," they're just saying a really big number, but it's also made up of smaller parts that are easier to understand.