760 likes | 780 Views
Practical Estimation Using Scientific Notation. Created by Dick Heckathorn. Can you quickly approximate an answer to the following problem?. How many seconds are there in one year?. Can you quickly determine which is larger?. 3684 x 27.36 x 416.3 ? or 63.72 x 273 x 4175 ?.
E N D
Can you quickly approximate an answer to the following problem? How many seconds are there in one year?
Can you quickly determine which is larger? 3684 x 27.36 x 416.3 ? or 63.72 x 273 x 4175 ?
Can you quickly approximate an answer to the following problem?
57,246.9318 5 ten-thousands 9 tenths 7 thousands 3 hundredths 2 hundreds 1 thousandths 4 tens 8 ten-thousandths 6 ones
A review of what happens to a number when it is multiplied by ten (10).
2 2 x 10 = 20 2 x 10 x10 = 200 2 x 10 x 10 x 10 = 2000 2 / 10 = 0.2 2 / 10 / 10 = 0.02 2 / 10 / 10 / 10 = 0.002
Number How number is formed 1 = 1 10 = 1 x 10 100 = 1 x 10 x 10 1000 = 1 x 10 x 10 x 10 10000 = 1 x 10 x 10 x 10 x 10 100000 = 1 x 10 x 10 x 10 x 10 x 10 1000000 = 1 x 10 x 10 x 10 x 10 x 10 x 10
Power Number How number is formed of 10 1 1 x no tens 100 10 1 x 10 101 100 1 x 10 x 10 102 1,000 1 x 10 x 10 x 10 103 10,000 1 x 10 x 10 x 10 x 10 104 100,000 1 x 10 x 10 x 10 x 10 x 10 105 1,000,000 1 x 10 x 10 x 10 x 10 x 10 x 10 106
Power of 10 Number How number is formed 100 1 1 10-1 0.1 1 / 10 10-2 0.01 1 / 10 / 10 10-3 0.001 1 / 10 / 10 / 10 10-4 0.0001 1 / 10 / 10 / 10 / 10 10-5 0.00001 1 / 10 / 10 / 10 / 10 / 10 10-6 0.000001 1 / 10 / 10 / 10 / 10 / 10 x 10
Scientific Notation Is a system in which the numbers are expressed as the product of the COEFFICIENT which is a number that is equal to or greater than one but less than ten and the appropriate POWER OF TEN
The Number 63847
63847 Same number in scientific notation 6.3847 x 104 Coefficient Power of Ten
Let us now examine the steps to change a number to scientific notation format.
Number to be Changed 76348
76348 First move the decimal point so that one non-zero digit is to the left of the decimal point. 7.6348
76348 7.6348 It was moved 4 places to the left.
76348 7.6348 The number is 10,000 (104) times smaller.
76348 7.6348 To make the number in scientific notation the same as the original number, what must we do to the powers of ten?
76348 7.6348 We must multiply the number by ten to the fourth power (4). 7.6348 x 104
Number to be Changed 0.000385
0.0003857 First move the decimal point so that one non-zero digit is to the left of the decimal point. 3.857
0.0003857 3.857 It was moved 4 places to the right.
0.0003857 3.857 The number is 10,000 (104) times larger.
0.0003857 3.857 To make the number in scientific notation the same as the original number, what must we do to the powers of ten?
0.0003857 3.857 We thus multiply 7.6348 by 10 to the minus four power (10-4). 3.857 x 10-4
Change the following number to scientific notation format. 724000 Check your answer on the next slide when finished.
724000 The answer is 7.24 x 104
Change the following number to scientific notation format. 0.0000517 Check your answer on the next slide when finished.
0.0000517 The answer is 5.17 x 10-5
Let us now solve a problem where the numbers are written in scientific notation.
The Problem (3.1 x 102) x (2.0 x 104)
(3.1 x 102) x (2.0 x 104) First separate the coefficients & powers of ten. (3.1 x 2.0) x (102 x 104)
(3.1 x 102) x (2.0 x 104) (3.1 x 2.0) x (102 x 104) Next show how the powers of ten are combined. (3.1 x 2.0) x 10(2 + 4)
(3.1 x 102) x (2.0 x 104) (3.1 x 2.0) x (102 x 104) (3.1 x 2.0) x 10(2 + 4) Finally finish the calculation. 6.2 x 106
Let us solve another problem where the numbers are written in scientific notation.