Adding and Subtracting Money Amounts
Questions from this book are taken from “Good Questions: Great Ways to
Differentiate Math Instruction.” by Dr. Marian Small and “Guide to
Effective Instruction K-6 Number Sense, Volume 2: Addition and
Subtraction”
Math Learning Goal:
• Students will communicate strategies they
use when adding and subtracting
numbers.
Grade 5/6
Materials
Big Ideas:
• It is important to recognize when each
operation is appropriate to use.
60 min
Part One:
Mind’s On
5 min.
Curriculum Expectations:
• add and subtract decimal numbers to hundredths,
including money amounts, using concrete
materials, estimation, and algorithms
• solve problems involving ...the addition and
subtraction of decimal numbers to hundredths,
using a variety of strategies
Small Group: Open Question
“Amanda used a calculator to add 7.45 and 2.39.
The calculator display showed 31.35. Explain why
this result is not reasonable.
Where do you think Amanda made her mistake?”
• students will discuss this question in pairs, and then
share their solutions with the class
• question
posted on
chart paper
or Smart
Board
Part 2:
Action!
35 min.
Pairs: Parallel Task:
the
teacher will present the following parallel task
•
to students:
• communicati
on checklist
on chart
paper
• handout with
Choice A:
the questions
St. Pius X School wants to raise $1550.00 for the
for students
Japan to help with earthquake relief. The primary
to read
grades raised $265.50. Grades 7 & 8 raised $502.34.
• chart paper
Next week, the junior grades are having a bake sale
and markers
to raise the rest of the money. How much money
• base 10
do they need to raise?
blocks or 10 x
10 grids
Choice B:
available
St. Pius X School wants to raise $500.00 for the Japan
to help with earthquake relief. The primary grades
raised $265.50. Grades 7 & 8 raised $104.25. Next
week the junior grades are having a bake sale to
raise the rest of the money. How much money do
they need to raise?
Pairs / Whole Group: Gallery Walk
• teacher will provide students with stickies and
Part 3:
have them rotate around the room and ask
Consolidate/
questions about communication : Example: How
Debrief
did you get this answer? etc.
• teacher will give students time to add to their
answers in a different colour of marker.
• students will share each other’s responses
• Teacher will record some of the strategies that
could be used in a highlights and summary chart
20 min
Strategies for Adding and Subtracting Decimals:
• open number line
• algorithm
• combining hundreds, tens, and ones then
subtracting
• mental math
Home Activity or Further Classroom Consolidation
• send home the “At Home Activity” on page 69 of
the Guide to Effective Instruction, K-6, Number
Sense, Volume 2 (see attached)
Name:___________________________________
Choice A:
St. Pius X School wants to raise $1550.00 for Japan to help with earthquake
relief. The primary grades raised $265.50. Grades 7 & 8 raised $502.34.
Next week, the junior grades are having a bake sale to raise the rest of the
money. How much money do they need to raise?
Choice B:
St. Pius X wants to raise $500.00 for Japan to help with earthquake relief.
The primary grades raised $265.50. Grades 7 & 8 raised $104.25. Next
week the junior grades are having a bake sale to raise the rest of the
money. How much money do they need to raise?