There were 1764 people at the soccer match on Sunday. a) Round this number off to the nearest 1000. b) 136 - c) 321 -

The number is 1764.

To round to the nearest 1000, we look at the hundreds digit. If the hundreds digit is 5 or greater, we round up the thousands digit. If it is less than 5, we keep the thousands digit the same.
The hundreds digit in 1764 is 7.
Since 7 is greater than or equal to 5, we round up the thousands digit (1) to 2. All digits to the right become 0.

The number 1764 rounded to the nearest 1000 is $\boxed{2000}$.