Counting with a Calculator

Transcription

1 Counting with a Calculator Objective To introduce counting up and back on the calculator. epresentations etoolkit Algorithms Practice EM Facts Workshop Game Family Letters Assessment Management Common Core State Standards Curriculum Focal Points Interactive Teacher s Lesson Guide Teaching the Lesson Ongoing Learning & Practice Differentiation Options Key Concepts and Skills Count forward and backward by 1s, s, 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 ] Key Activities Children learn to count up and back using a calculator. Ongoing Assessment: Recognizing Student Achievement Use Mental Math and Reflexes. [Number and Numeration Goal 1] Ongoing Assessment: Informing Instruction See page 3. Key Vocabulary program Materials Home Link 3 9 calculator overhead nickels and pennies (optional) overhead calculator (optional) 1 3 Playing Penny-Nickel Exchange per partnership: 0 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 Math Journal 1, p. 5 Children practice and maintain skills through Math Box problems. Home Link 3 10 Math Masters, p. 0 Children practice and maintain skills through Home Link activities. Minute Math + Minute Math +, pp. 10 and 6 Children practice addition and subtraction concepts. ENRICHMENT Checking Frames-and-Arrows Problems with a Calculator Math Journal 1, p. 3 calculator Children use their calculators to check solutions to Frames-and-Arrows problems. EXTRA PRACTICE Skip Counting Math Masters, p. 6 Children practice skip counting by counting up and back on number lines. 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. 11, 115 Lesson

2 Getting Started Mental Math and Reflexes Do stop-and-start counts by 5s, and then by 1s. Count by 5s beginning with 0. Stop at 5. Then continue counting by 1s to 9. 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. Home Link 3 9 Follow-Up 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 with a Calculator WHOLE-CLASS 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. Tell children that they are going to learn how to use a calculator to count. Review some of the basic rules for using calculators: 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: 0 up s 30 Unit 3 Visual Patterns, Number Patterns, and Counting

3 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 s, 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 Press ON/C. This clears your calculator.. Press 0. This is the starting number. 3. Press the + key. This tells the calculator to count up.. Press. This tells the calculator to count by s. Now the calculator is ready to start counting by s. Direct the class to do the following: Without clearing your calculator, press the number is in the calculator display? key. Which Without clearing your calculator, press the Which number is in the display now? 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: Start at: 0 up 5s NOTE Different calculators may have different programs for counting. If your class is using the Casio SL-50L, use the program that follows. 1. Press the key to clear the calculator.. Press the count up number, in this case. 3. Press to tell the calculator to count up.. Press the start number, in this case 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 s. 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 1, on the board: Start at: 1 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

4 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 31, 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 + key; to count back, press the key. Do a few more counts back from a given number on the calculator. Counting Up, Starting from Any Number WHOLE-CLASS Ask someone to supply the information for counting up by s, starting at 5. Write it on the board, as follows: Start at: 5 up s 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. 3 Unit 3 Visual Patterns, Number Patterns, and Counting

5 Ongoing Learning & Practice Date LESSON 3 10 Math Boxes 1. Odd or even? Student Page. Make sums of 10 pennies. Playing Penny-Nickel Exchange Children practice skip counting with money by playing Penny- Nickel Exchange. For detailed instructions, see Lesson -10. PARTNER odd odd even even Left Hand Right Hand Answers vary. Finding Sums of Three Numbers (Math Masters, p. 305) PARTNER 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. 3. Use a calculator. Count up by 3s. 0, 3, 6,, 1, 15,, 1,,, What is the number model? Fill in the circle next to the best answer A B C 3-7 D Math Journal 1, p. 5 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 (Math Journal 1, p. 5) Mixed Practice Math Boxes in this lesson are paired with Math Boxes in Lesson The skills in Problem preview Unit content. 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 (Math Masters, p. 0) Home Connection Children determine dime exchanges. They are asked to bring 10 dimes to school to add to their tool-kit coin collections. Minute Math+ WHOLE-CLASS Use Minute Math+, pages 10 and 6, to provide more practice with easy addition and subtraction concepts. Name HOME LINK 3 10 Family Note Dimes 1. How many? 5 10 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. Î 1 Â Â 1 Í Î 1 Í. How much money? ÂÂÎÎÎ 13 ÎÂÂÂÎÎÎ 19 ÂÂÂÂÂÂ 30 Practice Home Link Master Draw the hour hand and the minute hand on each clock half-past 7 o clock Math Masters, p. 0 Date half-past 3 o clock Lesson

6 Date LESSON 3 9 More Frames and Arrows 1. Fill in the frames. Count by 5s Add 5. Fill in the rule. Subtract 3. Fill in the rule and the frames. Add 3. Fill in the rule and the frames. Subtract 10 Student Page Sample answers given for Problems Differentiation Options ENRICHMENT Checking Frames-and-Arrows Problems with a Calculator (Math Journal 1, p. 3) 5 15 Min Algebraic Thinking To further explore calculators, children use their calculators to check the Frames-and-Arrows problems on journal page 3. 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. 5. Make up your own. Math Journal 1, p. 3 Answers vary. EXTRA PRACTICE Skip Counting (Math Masters, p. 6) 5 15 Min 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. Name Teaching Master Date LESSON 3 6 Using Number Lines Math Masters, p. 6 3 Unit 3 Visual Patterns, Number Patterns, and Counting