Hi there!
To estimate means to find something close to the number. In other words, you are approximating.
When it comes to estimating, there is a general rule you need to follow. This general rule tells you to look at the digit to the right of the digit you want to estimate, and if it is less than 5 then you round down, and if it is greater than 5 you round up.
3.15 ≈ 3
4.89 ≈ 5
There you go! I really hope this helped, if there's anything just let me know! :)
