When I was in school, I always felt that rounding decimals and estimating numbers was a waste of time. That’s because nobody ever explain to me how rounding and estimating could help me solve problems. There is a lot of math that needs to be precise in the real world however I find that most the math I do on a daily basis can be an estimate. I think that rounding and estimating help students become flexible with numbers.

The lesson that I am sharing today is rounding decimals. This is a topic that students have previous practice when they learned how to round whole numbers.
The Texas TEKS 5.2C reads “round decimals to tenths or hundredths.” The common core standard reads “use place value understanding to round decimals to any place.”

Most of us have probably heard a rhyme that similar to “Five or more? Raise the score. Four or less? Let it rest.” I am not 100% opposed to teaching students a rhyme, however I think students need to understand why the rhyme works. If students aren’t able to connect the rhyme to anything they will be less likely to remember it.
This lesson uses number lines to help students round. The last lesson I share, comparing decimals, also used number lines. Number lines are becoming one of my favorite math tools because they help students become more flexible with numbers. I will try to incorporate them as much as possible.

You can download the lesson and activities here. The lesson plan is in editable form for you to change as needed.