Bundling and Unbundling with Place Value Disks
Bundling and Unbundling with Place Value Disks is a Grade 5 math skill in Eureka Math where students use physical or drawn place value disks to represent regrouping in addition and subtraction — bundling 10 smaller units into 1 larger unit or unbundling 1 larger unit into 10 smaller units. This concrete strategy builds deep understanding of the regrouping algorithm for whole numbers and decimals.
Key Concepts
Bundling is composing a larger unit from 10 smaller units (e.g., $10 \times 1 \text{ tenth} = 1 \text{ one}$), which corresponds to multiplication by 10. Unbundling is decomposing a larger unit into 10 smaller units (e.g., $1 \text{ one} = 10 \text{ tenths}$), which corresponds to division by 10.
Common Questions
What does bundling mean in math?
Bundling means combining 10 units of one place value into 1 unit of the next higher place value. For example, bundling 10 ones creates 1 ten, or bundling 10 tenths creates 1 one.
What does unbundling mean in subtraction?
Unbundling means breaking 1 unit of a higher place value into 10 units of the next lower place value when you need more units to subtract. For example, unbundling 1 ten creates 10 ones.
How do place value disks make regrouping concrete?
Each disk represents one unit at a specific place value. Students physically move or draw disks to show bundling and unbundling, making the abstract regrouping process visible and tangible.
When is bundling and unbundling used beyond whole numbers?
The same strategy applies to decimals. You can bundle 10 hundredths into 1 tenth or unbundle 1 tenth into 10 hundredths when adding or subtracting decimal fractions.