Rounding Worksheets for the Naughty Number Nine
I've had quite a collection of rounding worksheets and rounding charts on the site for some time, and they've provided great practice for my two oldest daughters. Just recently, however, my third grade daughter started a unit on rounding at school and an inappropriate right turn on the rounding round-a-bout had me pulling over to revisit these worksheets.
The steps to round numbers are pretty easy. Find the digit that corresponds to the place value you're rounding, so for example if you are rounding to the nearest hundred, find the hundreds place. We typically call that the "target digit" or "target number" here. Then look for the next smallest place value just to the right of the target digit. If that second number is five or greater, round the target digit up, otherwise leave it alone, then zero out all the smaller place values. Sometimes you'll hear the basic rounding advice rhymed as, "Five or above, give it a shove. Four or less, give it a rest."
But, sometimes, when the target digit is a nine, we've got one teeny extra step that often gets rounded right out of the discussion. If we're rounding up a nine, that place value actually becomes a zero and the next larger place value gets incremented. In effect, we're carrying or regrouping that rounding into the next lane. It's a trivial step, and usually we've covered addition with carrying already so it's an easy point to miss in your explanation of the process.
That is, unless you've learned rounding completely algorithmically, which unfortunately, seems to be what poor daughter #3 has done. So we're back to doing a little bit of number line examples in conjunction with these new rounding worksheets that feature quite prominently potholes on the road in the form of that naughty number nine.
I hope if you're on the same road these worksheets get you out of the ditch.