Place Value and Rounding

Place value and rounding are the first two topics we covered in math this year. 

A solid understanding of both number place and number value is crucial for students as they begin working higher-level mathematics, such as addition and subtraction with regrouping, multi-digit multiplication and division. This becomes particularly important when using the standard algorithms.

In my class, I like to use Place Value Parkway to teach and review place value. We talk about how each number has a "house" (place) where they live. The numbers live in sets - ones live alone, tens live in groups of 10, hundreds in groups of 100, and so on. As more ones join the Ones House and they can create a group of ten or more, that group has to move next door to the Tens House where the Tens live. As more Tens move in and a group of Ten-Tens (1 hundred) can be formed, they move next door to the Hundreds House. 

Working with place value in this visual form helps students understand how numbers move fluently through both place and value.  When we moved into operations with regrouping, the students knew that if they had "too many" for a particular House, they would form a group of ten and move next door (or walk next door and ask to move a group to the previous house, as in subtraction).  This really helps visual and hands-on learners have a deeper understanding of place value. We also use base-ten blocks to create numbers and "move" number groups in addition and subtraction. 

Rounding is a first-of-the-year review topic as well. We use the rhyme "0-4, stay on the floor! 5-9, climb the vine!" to help remember whether a number should be rounded up or down.