The trickiest part for some children is figuring out what the choices are. For example, if I am rounding 361 to the nearest hundred, I need to find the closest multiples of 100. Children need to know that 361 is between 300 and 400. Once they have determined this, they can see that 361 rounds to 400 because there is a 6 in the tens place.
The children began to understand that sometimes you need to count with precise accuracy, but other times you can make an estimate. In situations that require only an estimate we round numbers.
Challenge your third grade mathematician to round the following numbers to the nearest hundred:
292
138
456
2,307
Happy rounding! :o)