Representing Decimals with Visual Models
Representing Decimals with Visual Models teaches Grade 6 students to match each digit of a decimal to a specific type of base-ten block: ones are represented by unit cubes, tenths by rods, hundredths by flats, and other place values by corresponding units. Covered in Illustrative Mathematics Grade 6, Unit 5: Arithmetic in Base Ten, this visual approach makes the base-ten structure of decimals concrete, supporting operations on decimals and comparison of decimal values.
Key Concepts
To represent a decimal number such as $A.BC$ using visual models, you match the digit in each place value to a specific number and type of block: The digit $A$ in the ones place is represented by $A$ large squares. The digit $B$ in the tenths place is represented by $B$ long rectangles. The digit $C$ in the hundredths place is represented by $C$ small squares.
Common Questions
How do you represent a decimal with visual models?
Match each digit to its place value block. For a decimal like 2.35, use 2 unit cubes (ones), 3 rods (tenths), and 5 small squares (hundredths).
What does each base-ten block represent for decimals?
Ones are unit cubes, tenths are rods (10 of them make 1 unit), hundredths are flat squares (100 make 1 unit), and thousandths are smaller cubes.
How does a visual model help with comparing decimals?
Comparing visual models shows which decimal takes up more space, making greater-than and less-than relationships intuitive.
Where is representing decimals with visual models in Illustrative Mathematics Grade 6?
This topic is in Unit 5: Arithmetic in Base Ten of Illustrative Mathematics Grade 6.
Why are visual models useful for decimal operations?
They make regrouping (carrying and borrowing) concrete. Students can physically trade blocks when adding or subtracting decimals.