Arithmetical Symbols

Basic Math Symbols

Symbol	Symbol Name	Meaning / definition	Example
=	equals sign	equality	5 = 2+3 5 is equal to 2+3
≠	not equal sign	inequality	5 ≠ 4 5 is not equal to 4
≈	approximately equal	approximation	sin(0.01) ≈ 0.01, x ≈ y means x is approximately equal to y
>	strict inequality	greater than	5 > 4 5 is greater than 4
<	strict inequality	less than	4 < 5 4 is less than 5
≥	inequality	greater than or equal to	5 ≥ 4, x ≥ y means x is greater than or equal to y
≤	inequality	less than or equal to	4 ≤ 5, x ≤ y means x is less than or equal to y
( )	parentheses	calculate expression inside first	2 × (3+5) = 16
[ ]	brackets	calculate expression inside first	[(1+2)×(1+5)] = 18
+	plus sign	addition	1 + 1 = 2
−	minus sign	subtraction	2 − 1 = 1
±	plus - minus	both plus and minus operations	3 ± 5 = 8 and -2
±	minus - plus	both minus and plus operations	3 ∓ 5 = -2 and 8
*	asterisk	multiplication	2 * 3 = 6
×	times sign	multiplication	2 × 3 = 6
⋅	multiplication dot	multiplication	2 ⋅ 3 = 6
÷	division sign / obelus	division	6 ÷ 2 = 3
/	division slash	division	6 / 2 = 3
—	horizontal line	division / fraction
mod	modulo	remainder calculation	7 mod 2 = 1
.	period	decimal point, decimal separator	2.56 = 2+56/100
ab	power	exponent	23 = 8
a^b	caret	exponent	2 ^ 3 = 8
√a	square root	√a ⋅ √a  = a	√9 = ±3
3√a	cube root	3√a ⋅ 3√a  ⋅ 3√a  = a	3√8 = 2
4√a	fourth root	4√a ⋅ 4√a  ⋅ 4√a  ⋅ 4√a = a	4√16 = ±2
n√a	n-th root (radical)		for n=3, n√8 = 2
%	percent	1% = 1/100	10% × 30 = 3
‰	per-mille	1‰ = 1/1000 = 0.1%	10‰ × 30 = 0.3
ppm	per-million	1ppm = 1/1000000	10ppm × 30 = 0.0003
ppb	per-billion	1ppb = 1/1000000000	10ppb × 30 = 3×10-7
ppt	per-trillion	1ppt = 10-12	10ppt × 30 = 3×10-10

Numbers

There are two kind of Numbers :
A Cardinal Number is a number that says how many of something there are, such as one, two, three, four, five.
An Ordinal Number is a number that tells the position of something in a list, such as 1st, 2nd, 3rd, 4th, 5th etc.

Cardinal			Ordinal
1	One		1st	First
2	Two		2nd	Second
3	Three		3rd	Third
4	Four		4th	Fourth
5	Five		5th	Fifth
6	Six		6th	Sixth
7	Seven		7th	Seventh
8	Eight		8th	Eighth
9	Nine		9th	Ninth
10	Ten		10th	Tenth
11	Eleven		11th	Eleventh
12	Twelve		12th	Twelfth
13	Thirteen		13th	Thirteenth
14	Fourteen		14th	Fourteenth
15	Fifteen		15th	Fifteenth
16	Sixteen		16th	Sixteenth
17	Seventeen		17th	Seventeenth
18	Eighteen		18th	Eighteenth
19	Nineteen		19th	Nineteenth
20	Twenty		20th	Twentieth
21	Twenty one		21st	Twenty-first
22	Twenty two		22nd	Twenty-second
23	Twenty three		23rd	Twenty-third
24	Twenty four		24th	Twenty-fourth
25	Twenty five		25th	Twenty-fifth
…	…		…	…
30	Thirty		30th	Thirtieth
31	Thirty one		31st	Thirty-first
32	Thirty two		32nd	Thirty-second
33	Thirty three		33rd	Thirty-third
34	Thirty four		34th	Thirty-fourth
…	…		…	…
40	Forty		40th	Fortieth
50	Fifty		50th	Fiftieth
60	Sixty		60th	Sixtieth
70	Seventy		70th	Seventieth
80	Eighty		80th	Eightieth
90	Ninety		90th	Ninetieth
100	One hundred		100th	Hundredth
…	…		…	…
1000	One thousand		1000th	Thousandth

Arithmetical/mathematical symbols are read like this:
a. Addition
3+9=12 three plus nine equals twelve
3+8 three plus eigh
4+4 How much are three and four?
4+4=8 Four and four are eight
5245+10=5255 Five thousand two hundred and forty-five plus ten is five thousand two hundred and fifty-five
45+70+152=267 Forty-five, seventy, and one hundred and fifty two added together are (or make) two hundred and sixty seven. The sun (or total) is two hundred and sixty-seven.


b. Subtraction
17-6 seventeen minus six
4259-200=? How much are four thousand two hundred and fifty-nine minus to hundred?
14310
-5210
9100
Nought from nought leaves nought. One from one leaves nought (or nothing). Two from three leaves one. I can’t take (or subtract) five from four, I must borrow ten; five from fourteen leaves nine. The difference (or the reminder) is nine thousand none hundred.

c. Multiplication
8x4 eight times four
1x1=1 once one is one


d. Division
6:3 six divided by three
100:5=? How much are one hundred divided by five?
750;50=15 seven hundred and fifty divided by fifty equals fifteen