Counting with
a Calculator
Objective To introduce counting up and back on the calculator.
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ePresentations
eToolkit
Algorithms
Practice
EM Facts
Workshop
Game™
Teaching the Lesson
Key Concepts and Skills
• Count forward and backward by 1s, 2s,
and 5s from a given number. [Number and Numeration Goal 1]
• Read numbers and symbols on a calculator. [Number and Numeration Goal 3]
• Use the +, -, and = symbols to count
forward and backward on a calculator. [Patterns, Functions, and Algebra Goal 2]
Key Activities
Children learn to count up and back using
a calculator.
Ongoing Assessment:
Recognizing Student Achievement
Use Mental Math and Reflexes. Family
Letters
Assessment
Management
Common
Core State
Standards
Ongoing Learning & Practice
1 2
4 3
Playing Penny-Nickel Exchange
per partnership: 20 pennies and
10 nickels, die (using a second die
is optional)
Children practice skip counting
with money.
Finding Sums of Three Numbers
Math Masters, p. 305
per partnership: 3 dice
Children practice adding three 1-digit
numbers.
Math Boxes 3 10
Curriculum
Focal Points
Interactive
Teacher’s
Lesson Guide
Differentiation Options
ENRICHMENT
Checking Frames-and-Arrows Problems
with a Calculator
Math Journal 1, p. 43
calculator
Children use their calculators to check
solutions to Frames-and-Arrows problems.
EXTRA PRACTICE
Skip Counting
Math Masters, p. 68
Children practice skip counting by counting
up and back on number lines.
Math Journal 1, p. 45
Children practice and maintain skills
through Math Box problems.
[Number and Numeration Goal 1]
Home Link 3 10
Ongoing Assessment:
Informing Instruction See page 232.
Key Vocabulary
program
Materials
Home Link 39
calculator overhead nickels and pennies
(optional) overhead calculator (optional)
Math Masters, p. 80
Children practice and maintain skills
through Home Link activities.
Minute Math +
Minute Math ®+, pp. 10 and 46
Children practice addition and
subtraction concepts.
Advance Preparation
Two calculator programs are included in this lesson. Before you begin this lesson, decide which program you
should teach based on the calculators available at your school. You should only present one program.
Teacher’s Reference Manual, Grades 1–3 pp. 114, 115
Lesson 3 10
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Getting Started
Mental Math and Reflexes
Home Link 3 9
Follow-Up
Do “stop-and-start” counts by 5s, and then by 1s. Count by 5s beginning
with 0. Stop at 25. Then continue counting by 1s to 29.
Put a collection of pennies and nickels on the overhead (or draw them on the board).
Count them in unison, first counting the nickels by 5s and then counting the pennies
by 1s. Repeat as time allows.
Children share strategies
for figuring out the missing rules.
Ongoing Assessment:
Recognizing Student Achievement
Mental Math
and Reflexes
Use Mental Math and Reflexes to assess children’s ability to count by 5s
and then by 1s. Children are making adequate progress if they are able to
count on by 1s after they have stopped counting by 5s. Some children
will be able to make the counting transition more easily than others.
[Number and Numeration Goal 1]
1 Teaching the Lesson
Counting Up and Back
WHOLE-CLASS
ACTIVITY
with a Calculator
Tell children that they are going to learn how to use a calculator
to count.
Review some of the basic rules for using calculators:
NOTE Most basic four-function calculators
provide for counting up and back. Read the
instruction manual for the calculator that your
class is using for a description of the counting
(constant) function.
Do not drop or throw calculators.
It is easier to use a calculator when it is on a firm, flat surface.
Press the middle of a key to make sure that only one key is
pressed at a time. Discuss the various meanings of the word
key and the meaning in this context.
Use only your finger to press a key.
Write the following information on the board:
Start at:
Count:
By:
230
0
up
2s
Unit 3 Visual Patterns, Number Patterns, and Counting
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Before you use the calculator to count, you must program it, or
get it ready to count. Discuss the various meanings of the word
program and the meaning in this context. Describe how to
program the calculator to count up by 2s, as children follow along
on their calculators. You may find it helpful to use an overhead
calculator. Use the program that follows if your class is using the
TI–108.
1. Press
ON/C
. This clears your calculator.
2. Press 0. This is the starting number.
3. Press the
+
key. This tells the calculator to count up.
4. Press 2. This tells the calculator to count by 2s.
Now the calculator is ready to start counting by 2s. Direct the
class to do the following:
=
●
Without clearing your calculator, press the
number is in the calculator display? 2
key. Which
=
●
Without clearing your calculator, press the
Which number is in the display now? 4
key again.
=
●
Continue to press the
key. (Each time, the class calls out
the number in the display.)
Repeat the procedure, this time counting up by 5s, starting at 0.
Write the following information on the board:
NOTE Different calculators may have
different programs for counting. If your class
is using the Casio SL-450L, use the program
that follows.
1. Press the
key to clear the
calculator.
2. Press the count up number, in this
case 2.
3. Press
to tell the calculator to
count up.
Start at:
Count:
By:
0
up
5s
4. Press the start number, in this case 0.
5. Press the
key to run the program.
You may enter a new starting number and the
key, and the calculator will continue to
count by 2s.
To count back, press
.
Have a volunteer describe how to program the calculator to count
by 5s, as the class follows along.
Next, write the information for counting back by 1s, starting at
12, on the board:
Start at:
Count:
By:
12
back
1s
NOTE Some people find it helpful to use
the nonwriting hand for calculator keying
while keeping the writing hand available for
recording. In a playful, challenging way, see
if children can do the counts using their
nonwriting hands.
Lesson 3 10
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Adjusting the Activity
=
Describe what happens when you press the
key again after 0 has
been displayed. You get –1 Do this several times. What are these numbers
called? Negative numbers
A U D I T O R Y
K I N E S T H E T I C
T A C T I L E
V I S U A L
Describe how to program a calculator to count back. Use the
steps taught on page 231, but press
–
instead of
+
.
Ask: How is programming the calculator to count up different from
programming it to count back? To count up, press the
to count back, press the
––
+
key;
key.
Do a few more counts back from a given number on the calculator.
Counting Up, Starting
WHOLE-CLASS
ACTIVITY
from Any Number
Ask someone to supply the information for counting up by 2s,
starting at 5. Write it on the board, as follows:
Start at:
Count:
By:
5
up
2s
Give children a couple of minutes to program their calculators to
=
do this count. Children should press the
key a few times to
check that they have programmed their calculators correctly. Have
a volunteer describe what he or she did as the class follows along.
Ask: How is programming the calculator to count up from 5
different from programming it to count up from 0? 5 is used as
your start number rather than 0.
Do a few more counts up, starting with numbers other than 0.
Ongoing Assessment: Informing Instruction
Watch for children who do not clear their calculators before starting a new count.
232
Unit 3 Visual Patterns, Number Patterns, and Counting
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Student Page
2 Ongoing Learning & Practice
Playing Penny-Nickel Exchange
Date
LESSON
Math Boxes
3 10
1. Odd or even?
Left Hand
PARTNER
ACTIVITY
odd
Children practice skip counting with money by playing PennyNickel Exchange. For detailed instructions, see Lesson 2-10.
Finding Sums of Three Numbers
2. Make sums of 10 pennies.
PARTNER
ACTIVITY
even
Right Hand
7
3
4
6
2
8
Answers vary.
odd
even
3. Use a calculator.
4. What is the number
Count up by 3s.
(Math Masters, p. 305)
0,
9
18
27
Provide pairs of children with 3 dice. Children take turns rolling
the dice, writing addition number sentences representing the dots
shown, and finding the sums.
model?
12
21
30
,
,
,
Fill in the circle next to
the best answer.
6,
3,
15
24
,
,
,
,
0 1 2 3 4 5 6 7 8 9 10 11
A
3+5=7
B
4+3=7
C
3-4=7
D
3+4=7
Math Journal 1, p. 45
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For one roll, have children draw the faces of the 3 dice and
write the number model on an Exit Slip (Math Masters, page 305).
Ask: Would the sum be the same if you added the numbers in a
different order? Sample answer: Yes, it does not matter which
order you add the numbers; you will still get the same sum.
Math Boxes 3 10
INDEPENDENT
ACTIVITY
(Math Journal 1, p. 45)
Mixed Practice Math Boxes in this lesson are paired with
Math Boxes in Lesson 3-13. The skills in Problem 4
preview Unit 4 content.
Home Link Master
Name
Date
HOME LINK
3 10
Writing/Reasoning Have children draw, write, or
verbalize an answer to the following question: How do you
find a missing number to make a sum of 10? A reasonable
answer should describe an addition strategy such as using 10
pennies or counting on a number line.
Home Link 3 10
INDEPENDENT
ACTIVITY
Family
Note
Dimes
Note that Î means “penny,” Â means “nickel,” and Í means “dime.”
IMPORTANT: Please send 10 dimes with your child to class tomorrow.
Please return this Home Link to school tomorrow.
1. How many?
5 Î=1Â
2 Â=1Í
10 Î = 1 Í
2. How much money?
ÂÂÎÎÎ =
ÎÂÂÂÎÎÎ
(Math Masters, p. 80)
ÂÂÂÂÂÂ =
Home Connection Children determine dime exchanges.
They are asked to bring 10 dimes to school to add to their
tool-kit coin collections.
WHOLE-CLASS
ACTIVITY
Use Minute Math+, pages 10 and 46, to provide more practice
with easy addition and subtraction concepts.
¢
19
30 ¢
=
¢
Practice
Draw the hour hand and the minute hand on each clock.
3.
4.
11
10
12
1
2
9
Minute Math +
13
3
8
4
7
6
5
half-past 7 o’clock
11
10
12
1
2
9
3
8
4
7
6
5
half-past 3 o’clock
Math Masters, p. 80
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Student Page
3 Differentiation Options
Date
LESSON
More Frames and Arrows
3 9
1. Fill in the frames.
Rule
Count by 5s
Add 5
15
20
25
30
35
40
ENRICHMENT
Checking Frames-and-Arrows
Sample answers given for Problems 2–4.
2. Fill in the rule.
Rule
Subtract 2
20
18
16
14
12
INDEPENDENT
ACTIVITY
5–15 Min
Problems with a Calculator
10
(Math Journal 1, p. 43)
3. Fill in the rule and the frames.
Rule
Add 3
7
10
13
16
19
22
70
60
50
40
Algebraic Thinking To further explore calculators, children use
their calculators to check the Frames-and-Arrows problems on
journal page 43. The first frame tells children which number to
–
start with; the rule tells whether to enter + or
and which
number to enter and count by.
4. Fill in the rule and the frames.
Rule
Subtract 10
90
5. Make up your own.
80
Answers vary.
EXTRA PRACTICE
Rule
Skip Counting
Math Journal 1, p. 43
INDEPENDENT
ACTIVITY
5–15 Min
(Math Masters, p. 68)
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Have children count up and back on number lines to practice skip
counting. For each number line, give oral directions to children
telling them what to count by and whether to count up or back.
NOTE Remember to allow time for the
Mental Math and Reflexes routine every day.
The skills addressed will help to develop
children’s problem-solving skills.
Teaching Master
Name
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
8
7
6
5
4
3
1
1
0
0
2
8
7
6
5
4
3
8
1
0
2
3
4
5
6
7
8
7
6
5
4
3
1
0
2
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
Using Number Lines
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
2
36
Date
9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25
LESSON
Math Masters, p. 68
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234
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Unit 3 Visual Patterns, Number Patterns, and Counting
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