Regrouping with Popsicle Sticks: Double-Digit Subtraction
Can you break a ten? An everyday exchange of money can help students think about regrouping to subtract. Students will use bundled popsicle sticks to see how values grouped into tens can be regrouped into ones to allow us to subtract.
Students will be able to perform two-digit subtraction with regrouping.
The adjustment to the whole group lesson is a modification to differentiate for children who are English learners.
EL adjustments
Introduction
(5 minutes)
Ask your students, "If you had a ten dollar bill and you needed to pay a friend back for the six dollars she lent you, what could you do?"
Take student responses. If no one suggests breaking the ten dollar bill and exchanging it for smaller bills, then add suggest it.
If you choose to regroup the ten dollar bill for smaller bills, how might that look? (You could break the ten dollar bill with 10 one dollar bills or a five and five ones.)
Explain that understanding how to exchange a ten dollar bill for ten one dollar bills will help them with the math strategy they will learn today.
Beginning
Have students turn and talk to a supportive peer or one with the same home language (L1), if possible.
Allow students to respond with a visual to support their explanation.
Intermediate
Use real or pretend money to serve as manipulatives in the example.
Define words that apply to the example problem, such as exchange, lent, regroup.