Unit 5, Lesson 15
Estimate and Subtract
Grade 5
Preparation
Lesson Narrative
In a previous lesson, students found decimal differences in a way that made sense to them. In this lesson, students see that the standard algorithm for subtraction, which they have used in IM Grade 4, also works for decimals. Students then estimate differences and find their values. Students are not required to use the standard algorithm, but see how it is an efficient way to subtract.
The lesson also includes an optional activity where students analyze an error in subtracting decimals with the standard algorithm. This activity can be used if students are struggling with combining digits with the same place values in two numbers when they add and subtract.
Display the Decimal Subtraction chart from a previous lesson to be used during Lesson Synthesis.
- Action and Expression
None
- Describe (orally and in writing) the steps in a worked example of the standard algorithm for subtracting decimals to hundredths.
- Use place value strategies to estimate and calculate the difference of decimals to hundredths.
- Let’s use place value to subtract decimals.
Required Preparation
None
Teacher Reflection Questions
What aspects of the math community are going well? What aspects would you like to work on? What actions can you take to improve those areas?