Unsquaring Numbers
Everyday Math Lesson 1.8
Lesson Objectives
• I can tell the difference between powers of
ten written as ten raised to an exponent.
• I can show powers of 10 using whole number
exponents
Vocabulary
• Add the following vocabulary
word to your vocabulary chart:
–Square Root
Mental Math
5x6
3x9
7x7
6x6
9x5
7*8
6*7
9x6
8x6
6x9
7*6
6*8
7*9
8*7
9*7
8*9
Math Message
• Find the numbers that make these
statements true. If you need counters,
you may use them to help you.
___x ___ = 4
___² = 81
“Unsquaring” Numbers
• What is the difference in squaring and unsquaring a
number?
– When you multiply a number by itself, you square the
number.
• 4 x 4 = p – Square the number 4 to find P
• P = 16
– When you “unsquare” a number, you must undo the
operation in order to find the number that was
squared.
• N * N = 16
• N=4
Let’s try some more!
• In your work journal “unsquare” the following
numbers:
– 196
– 10,000
– 900
– 3, 136
Your Turn
• With your assigned partner, complete
problems 1 and 2 on Student Journal Page 23.
• You will have 15 minutes to work, when time
is called be ready to share your answers.
Finding the Square Root
• How can we check our answers to problem
one?
– Multiply the square root of a number by
itself. The symbol for square root is √
– You can use the square root key on your
calculator to help you find these answers.
• EX: 8² = 8 x 8 = 64 The square root of 8 is
64 and the square root of 64 is 8.
Using the √ key on your
calculator
• Check your answers to problem 2 by
completing the following:
– Enter the number for which you are trying to find
the square root.
– Press the √ key, and then press = or enter.
– If the answer is a whole number, then the number
you entered is sqaure.
– If the answer is a decimal number, the number
you entered is NOT square.
Your Turn!
• With your assigned partner, complete Student
Journal Page 23 problems 3-6.
• You may also finish checking the answers to
problem 2 with your calculators.
• You will have 15 minutes to work, when time
is called be ready to share your answers.
Writing/Reasoning
• Get out your Work Journal.
• Write a response to the following: Was Jason
correct when he said that 64 is a prime
number in Problem 3? Explain your answer.
Use vocabulary words when appropriate.
Let’s Play Multiplication Top-It
• Read the directions for playing this game on
SRB page 333 and 334.
• You will use a record sheet to keep track of the
game. This will be your exit slip for today’s
class.