Flashcards
powers and roots
Cards in this deck (20)
- 1what are powers?9 is a square number.
Square of 9 squares
3 times 3 = 9
3 times 3 can also be written as 3^2.( 3 to the power of 2) This is pronounced "3 squared". - 2what is index form?The notation 3^2 and 2^3 is known as index form. The small digit is called the index number or power.
- 3what is 7^2?7 x 7 = 49
- 4what is 5^3?5 x 5 x 5 = 125
- 5what is 2^4?2 x 2 x 2 x 2 = 16
- 6what is 2^7?2 x 2 x 2 x 2 x 2 x 2 x 2 = 128
- 7what is square root?The opposite of squaring a number is called finding the square root.
Eg:
The square root of 16 is 4 (because 4^2 = 4 times 4 = 16). - 8what is the square root of 4?2 is the square root of 4.
2 x 2 = 4 - 9what is the square root symbol?This is the square root symbol:
- 10what is the square root of 36?The square root of 36 is 6.
- 11what is the square root of 81?The square roots of 81 is 9
- 12what is cube root?The opposite of cubing a number is called finding the cube root.
Eg:
The cube root of 27 is 3 (because 3 times 3 times 3 = 27)
- 13what is the cube root of 8?2 is the cube root of 8.
2 x 2 x 2 = 8 - 14what is the symbol of cube root?This is the cube root symbol:
- 15what is the cube root of 125?The cube root of 125 is 5.
5 x 5 x 5 = 125 - 16what is the cube root of 64?4 is the cube root of 64?
4 x 4 x 4 = 64 - 17—
- 18Index laws for multiplicationMultiplication
How can we work out 2^3 x 2^5?
2^3 = 2 x 2 x 2
2^5 = 2 x 2 x 2 x 2 x 2
so 2^3 x 2^5 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 = 2^8
There are 3 twos from 2^3 and 5 twos from 2^5, so altogether there are 8 twos.
The index 8 can be found from adding the indices 3 and 5. Remember, this only works when we are multiplying powers of the same number together - 19index laws of divisionThere are 5 twos from 2^5 and 3 twos from 2^3, so after dividing there are 2 twos. The index 2 can be found from subtracting the indices, 5 - 3 = 2. Remember, this only works when we are dividing powers of the same number.
- 20what is the square root of 100?10 is the square root of 100.
10 x 10 = 100
Information
- Description
- KS3 - maths - number
- Created by
- Eesha sunda · Jul 2016
- Updated
- Jul 19, 2016
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