“Closer To” helps scholars build their skills within rounding. When problem-solving, this skill can help scholars to estimate and determine the reasonability of their answer. This mini-lesson asks scholars to round a number to a given whole number or fraction using the number line model as a visual representation.
What is the structure?
“Closer To” Mini-lesson Structure
Launch
1 minute
Introduce a class number line with two numbers filled in at the start and end point. (e.g. 100 on the left side of the line and 200 on the right side of the line)
Activity
3 minutes
Introduce another number that falls between the first two. (e.g. 182) Ask scholars where it would go on the number line and which of the other two numbers it’s closer to.
Scholars use whiteboards to plot their answers and discuss with partners. The whole class discusses which of the 2 numbers it’s closer to and how they know.
Mark it on the class number line.
Repeat this with more numbers that fall between the original two numbers, always asking scholars to demonstrate their reasoning.
Discourse
10 minutes
Discuss patterns that occur and make conjectures about rounding, place value, or related mathematical ideas.
Exit Ticket
1 minute
Provide scholars with an exit ticket to assess the goals of the mini-lesson.
What are the top instructional moves for this Mini-lesson?
Choosing Numbers: Be purposeful in your number choices— both the numbers you use as the range for the number line and the numbers you ask scholars to plot. Use scholar work, gaps in understanding, and information from the Math lesson to inform your choices and sequence. Numbers are typically provided in the lesson plan.
Use models rather than rhymes or rules: Illustrate scholars’ thinking using number lines to support conceptual understanding. Teaching rounding “rules” or tricks puts the focus on memorization without true understanding.
Valorize a variety of strategies: Scholars may find it helpful to locate the midpoint between the two endpoints, to calculate the difference between the given number and each end point, or to use some other strategy. Acknowledge that there are a variety of ways to think about the problem, and that certain strategies may work better for certain numbers. Do not make blanket mandates for scholars to use a specific strategy every time.
Closer To example
Is 0.456 closer to 0 or 1? Closer to 0.4 or 0.5?
Is 0.381 closer to 0 or 1? Closer to 0.3 or 0.4? Closer to 0.38 or 0.39?
Is 0.095 closer to 0 or 1? Closer to 0.09 or 0.10? Why do we generally “round up”?
resources
Related content
Access a wide array of articles, webinars, and more, designed to help you help children reach their potential.
