Victor 900 manual Lesson 5 Repetitive Subtraction and Addition

Lesson 5: Repetitive Subtraction and Addition

TEACHER’S GUIDE

Lesson 5: Repetitive Subtraction and Addition

Overview	Use the calculator to subtract or add repetitive
	numbers using the constant function.
Teacher Materials	“Repetitive Subtraction and Addition” and “Fastest
	Fingers” transparencies.
Student Materials	Pencil, Calculator, and “Constant Calculations”
	worksheet.
Keys Introduced	Constant function using the = Key.
Teaching Notes	Ask your students to enter 10 on the calculator and
	add 10 to the total every time you snap your fingers.
	Snap your fingers 4 times and compare the answers
	from several students (the answer should be 50).
	Tell the students how the calculator stores the last
	command and number entered. This is called the
	constant function. The constant function helps reduce
	mistakes and save time when you must subtract, add,
	divide, or multiply the same number many times.
	Ask your students to again enter 10 on the calculator
	and add 10 every time you snap your fingers. Snap
	your fingers 4 times and compare the answers.
	Note: The constant is removed from memory when
	the	ON/AC	button is pushed.
	Use the “Fastest Fingers” transparency to play a fun
	game that reinforces the constant function.
	Use the “Constant Calculations” worksheet for
	practice.

Victor 900 Calculator Teacher’s Guide 17