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Powers and Exponents. Powers and Exponents. A power is represented with a base number and an exponent. The base number tells what number is being multiplied. The exponent, a small number written above and to the right of the base number, tells how many times the base
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Powers and Exponents • A power is represented with a base number and an exponent. The base number tells what number is being multiplied. The exponent, a small number written above and to the right of the base number, tells how many times the base number is being multiplied.
Powers and Exponents • The exponent tells you how many times to write the base number – then put multiplication signs between the numbers.
Powers and Exponents • For example: 23 Write the base number – 2 – 3 times, and place multiplication symbols between: 2 x 2 x 2 = 8 so: 23 = 8 ______________________________ 44= 4 x 4 x4 x 4 = 128
Squaring Numbers The most common exponent is 2 – when you have a base number with an exponent of 2, it’s called squaring a number. To square a number, just multiply it times itself. Example: What is 3 squared? 3 Squared= 3 × 3 = 9
Squaring Numbers • 72= • 102= • 82= • 22= • 62= • 92= • 02=
Squaring Numbers • 72= 7x7 = 49 • 102= 10x10 = 100 • 82= 8x8 = 64 • 22= 2x2 = 4 • 62= 6x6 = 36 • 92= 9x9 = 81 • 02= 0x0 = 0
Square Roots • The Square Root Symbol/Radical Symbol • This is the special symbol that means "square root", it looks like a division sign with a tail, and actually started hundreds of years ago as a dot with a flick upwards. • You can read it as “What number times itself equals”.
Square Roots • You can use the radical symbol like this: (you would say "the square root of 9 equals 3") • The square root of 9 is 3, because when 3 is multiplied by itself you get 9.
Mostly, you’ll see the “perfect squares” on the GED • If you’re asked to find the square root and it’s not a whole number, use the following method:
Example: What is the square root of 32? Now, if you have a calculator, you can just punch it in and get the answer using the shift key + the square (x2) button.
Example: What is the square root of 32? If you don’t have a calculator, figure out between which two whole numbers the square root must be.
Example: What is the square root of 32? 52is 25, which is too little, and 62 is 36, which is too much. Therefore, the square root of 32 must be a number between 5 and 6. You won’t get the exact answer, but you can get close.
The square root of 40 is between what two whole numbers? 62= 36 and 72= 49, so the square root of 40 is between 6 and 7
You should now be able to do the powers and roots practice on page 114 in your book. • Next up is Order of Operations