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Numbers
Numbers are our way to quantify, label, and organize the world around us in a logical manner. However, the systems used to obtain this goal differ geographically, historically, and by relative utility. All questions pertaining to numbers, including historic labeling systems, bases of numerical systems, constants, and the various ways they're grouped together, should be placed into this category.
46,867 Questions
Would a negative minus a negative automatically become plus?
No, for example. -8- -3 = -5, because it's as if you added 3 to negative 8, which brings you to -5.
How are the numbers in the decimal system called?
1. 1.098
one is one
0 is zero tenths
9 is nine hundredths
8 is eight thousandths
Thirty nine is not a prime number because it has more than two factors one and itself and three. To be a prime number it must only have one and itself...
How do you turn 7.016 into a mixed number?
mixed means whole number and fraction
7.016 means 7 and 16 in the thousandths place
So, 7.016 = 7 16/1000
In lowest terms, 7 2/125
Can Planck's constant is zero?
No. It is a very small number (approximately 6.626 × 10-34 joule-second) but that is NOT zero
The canonical example is the square root of -1.
Mathematicians use the symbol i to represent it, electrical engineers use j because i is already busy.
What is a number that is not real?
i, which is *defined* as the square root of -1, is imaginary, not real.
The square root of -1 is i, the square root of -4 is 2i, the square root of -9 is 3i, etc.
i, 2i, 3i, 4i, 5i, etc. = non-real numbers.
'Real' numbers are all of the numbers in the world: integers, rational numbers, irrational numbers, positive, negative, etc.
Non-real (imaginary) numbers are numbers that exist only in theory such as the square root of a negative number, or the roots of an equation that never reaches the x-axis. (They are noted with the lowercase letter i for imaginary). This concept is very distant to most people outside of math classes.
How do you do decimal word form?
The number before the decimal point is written in word form without suing "and". Next an "and is used where the decimal point appears. Then the number after the decimal point is written out in word form (again, without using "and"). Finally, the inverse power of ten is written and this is based on the number of digits after the decimal point.For 1 digit: tenths
2 digits: hundredths
3 digits: thousandths
4 digits: ten thousandths
5 digits: hundred thousandths
6 digits: millionths
and so on.
What is the first 200 odd numbers added together?
You can use the formula for the sum of an arithmetic sequence for this one. The first odd number would presumably be 1; the interval between one number and the next is 2.
Is 67 divided by a rational or irrational?
You can divide 65 by rationals and irrationals:
Divided by a rational: 65 ÷ 13/2 = 10
Divided by an irrational: 65 ÷ √13 = 5√13
How do you round 3951.675 to 3 significant digits?
- write down the first three digits.
- look at the fourth digit
- if it is 5 or more, add one to what you have written down so far (ie round up)
- replace all digits from the fourth onwards by zeros.
- if any zero after the third digit is after a decimal point, rub them out.
That's HOW to do it, this is it being done:
3951.675 to 3 sig fig is 3950
