Making Math Matter: Adding & Subtracting Decimals

Learning Resource Type

Classroom Resource

Subject Area

Mathematics

Grade(s)

5

Overview

In this video, teachers will learn classroom strategies for teaching decimal addition and subtraction in this professional development video from Making Math Matter.

Mathematics (2019) Grade(s): 5

MA19.5.3

Using models and quantitative reasoning, explain that in a multi-digit number, including decimals, a digit in any place represents ten times what it represents in the place to its right and $\frac{1}{10}$ of what it represents in the place to its left.

UP:MA19.5.3

Vocabulary

  • Digit
  • Decimal
  • Decimal point
  • Thousandths
  • Hundredths
  • Tenths
  • Base-ten
  • Expanded form
  • Place value
  • Power of 10
  • Factor
  • Base
  • Exponent
  • Product

Knowledge

Students know:
  • Each place value position represents 10 times what it represents in the place to its right.
    Example: In 433, the underlined 3 represents 3 tens and has a value of 30 which is ten times the value of the 3 ones to its right.
  • Place value understanding is extended to apply reasoning that a place value position represents 1/10 of what it represents in the place value to its left.
    Example: In 433, the underlined 3 represents 3 ones and has a value of 3 which is one-tenth of the value of the 3 tens or 30 to its left.
  • A given number multiplied by a power of 10 shifts the digits in the given number one place value greater (to the left) for each factor of 10.-A given number divided by a power of 10 shifts the digits in the given number one-tenth of the value (to the right) for each factor of 10.

Skills

Students are able to:
  • Reason and explain the relationship between two successive place values.
  • Explain patterns of zeros of the product when multiplying by powers of 10.
  • Explain patterns in placement of decimals when multiplying or dividing by power of 10.
  • Write powers of 10 using exponential notation.

Understanding

Students understand that:
  • The relationship of adjacent places values in the base ten system extend beyond whole numbers to decimal values.
  • Multiplying or dividing by a power of 10 shifts the digits in a whole number or decimal that many places to the left or right respectively.
Mathematics (2019) Grade(s): 5

MA19.5.4

Read, write, and compare decimals to thousandths.

UP:MA19.5.4

Vocabulary

  • Compare
  • Decimal
  • Thousandths
  • Hundredths
  • Tenths
  • Symbol
  • Greater than
  • Less than
  • Equal
  • Place value strategy
  • Expanded form
  • Expanded notation

Knowledge

Students know:
  • How to read and write whole numbers in standard form, word form, and expanded form.
  • How to compare two whole numbers using place value understanding.
  • Prior place value understanding with whole numbers is extended and applied to decimal values.
  • Recognize and model decimal place value using visual representations to compare.

Skills

Students are able to:
  • Read and write decimal values in word form, standard form, and expanded form.
  • Compare decimals to thousandths using , or = .

Understanding

Students understand that:
  • the adjacent place value relationship in the base ten system extends to decimals and is used to write decimals in expanded form and compare decimals.
Mathematics (2019) Grade(s): 5

MA19.5.8

Add, subtract, multiply, and divide decimals to hundredths using strategies based on place value, properties of operations, and/or the relationships between addition/subtraction and multiplication/division; relate the strategy to a written method, and explain the reasoning used.

UP:MA19.5.8

Vocabulary

  • Decimal
  • Tenths
  • Hundredths
  • Place value

Knowledge

Students know:
  • Strategies based on place value understanding, properties, and relationship between operations to find the sum, difference, product, and quotient of whole numbers.
  • How to write decimal notation for fractions with denominators of 10 or 100.
  • Use estimation strategies to assess reasonableness of answers.

Skills

Students are able to:
  • Use concrete models, drawings, and strategies to add, subtract, multiply, and divide decimals.
  • Relate strategies for operations with decimals to a written method and explain reasoning used.
  • Solve real-world context problems involving decimals.

Understanding

Students understand that:
Problems involving operations with decimals
  • Can be solved using a variety of strategies based on place value, properties of operations, or the relationship between the operations.
  • Can be illustrated using concrete models or drawings.

CR Resource Type

Audio/Video

Resource Provider

PBS

License Type

CUSTOM
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