To round a number to the nearest thousand, you need to look at the hundreds digit and decide whether to round up or down. If the hundreds digit is 5 or more, you round up. If it is 4 or less, you round down. For example:
13145978 has a hundreds digit of 9, which is more than 5, so you round up to the next thousand: 13146000.
13145478 has a hundreds digit of 4, which is less than 5, so you round down to the previous thousand: 13145000.
You can use the rounding calculator to check your answers or try different rounding modes and levels of precision.
1000
1000
1000
1000
176 rounded to the nearest 1000 is 0
1000
0
1000
7000
214357000
33000
128000