Rounding to significant figures
The word significant means "big" or "important". A significant life event might be getting your GCSE results or starting your first job. When we talk about significant figures in maths, we're kind of doing the same thing.
If you take the number 3268, the 3 is worth the most, even though 3 on its own is smaller than 6 or 8. This is because the 3 represents 3 thousand, which is much bigger (more significant) than the 6 (tens) or 8 (units). 3 is the first significant figure in the number 3268.
Similarly, 2 (2 hundred) is the second significant figure, 6 is the third and 8 is the fourth.
If you're asked to round to a certain number of significant figures, just count through the number until you reach the digit you need, then round exactly as you would do for tens, whole numbers or decimals.