8 • Casio Fx 55
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The Smart Calculator
Exploring Patterns
Using the Activity:
Students discover how to use the
and the
keys to find products that form patterns.
• The
key can be used to enter the first factor into the memory of the calculator.
• The
key can be used to recall the first factor and to find other products.
Example For the first product in problem 1, 16
X
1
16. For the second product,
X
10 = 160. Continue using a similar key sequence to find all of the products. Note: The
key should be used to clear the memory before a new first factor is entered.
Assessment Encourage students to check their final products to be sure they see a pattern.
Answers
See example for key sequence. l. 16; 160; 1,600; 16,000. The first two digits are 1 and 6. Each product has one
more 0 at the end than the previous product. 2. 1,089; 2,178; 3,267; 4,356. The first digits are the whole
numbers in order starting with 1, the second digits are whole numbers in order starting with 0, the third digits
are whole numbers starting at 8 and going backwards, and the last digits are whole numbers starting at 9 and
going backwards. 3. 98,901; 87,912; 76,923; 65,934. The first digits are whole numbers starting with 9 and
going backwards, the second digits are whole numbers starting with 8 and going backwards, the third digits are
all 9s, the fourth digits are whole numbers in order starting with 0, and the last digits are whole numbers in
order starting with 1. 4. 9,801; 98,901; 989,901; 9,899,901. The first digits are all 9s, the second digits are all
8s, the next to last digits are all 0s, and the last digits are all 1s. Each product has one more 9 after the 8 than
the previous product. 5. 72; 792; 7,992; 79,992. The first digits are all 7s and the last digits are all 2s. Each
product has one more 9 after the 7 than the previous product. 6. 111,111; 222,222; 333,333; 444,444. The first
product is all 1s, the second all 2s, the third all 3s, and the fourth all 4s.
Thinking Cap
As an extension, students continue the pattern they found in each problem. They can use the key
sequence they discovered to check their answers.
Topic:
Number Patterns
Objective:
To use the calculator to discover
and extend patterns.
NCTM Standards:
Communication,
Patterns, and Functions
