Rounding
When rounding a number, you first have to know what place value you are rounding to. After finding the correct place value, you have to look at the number to the right of it. If the number to the right is between 0 and 4, keep the original place value the same number. If the number to the right is between 5 and 9, add one to the original place value.
Explore the app to see place value and rounding in action.
Click on the place value you want to round to.
Change the number with the button at the bottom of the applet.