#638 Synced about.md and exercises introduction.md with new introduct…

…ion.md (#653)

* Synced about.md and exercises introduction.md wih numbers introduction.md file

* Retained Casting & Precision as per comment

concepts/numbers/about.md

@@ -1,5 +1,4 @@
 # About
-
 The built-in number types in C++ can be divided into integers and floating points.
 Integers are whole numbers like `0`, `691`, or `-2`.
 Floating point numbers are numbers with a decimal point like `6.02214076`, `0.1`, or `-1.616`.
@@ -42,8 +41,48 @@ When one of the involved types is a floating-point type, the result will also be
 `5.0 / 2` and `5 / 2.0` will return `2.5`.
 `%` is the remainder operator and will return the remainder of an integer division: `5%3` is `2`.
 
+## Assignment operator
+
+The assignment operator assigns a variable with a literal.
+Always takes place from right to left, and never the other way around.
+
+```cpp
+int length = 5;
+int width = 2;
+length = width;
+```
+Here integer value `5` is assigned to the variable `length`.
+Then integer value `2` is assigned to variable `width`.
+Finally value of `width` is copied to the variable `length` and the earlier value `5` will be lost.
+Consider also that we are only assigning the value of `width` to `length` at the moment of the assignment operation.
+Therefore, if the value of `width` changes at a later moment, it will not affect the value taken by `length`.
+
+Assignment operator can be combined with the other operators(arithmetic & bitwise) known as `compound assignment` operators `+=`, `-=`, `*=`, `/=`, `%=`.
+These operators modifies the current value of a variable by performing an operation on it.
+
+```cpp
+// we start with 0 people
+int people{};
+// we need 0 eggs
+int eggs{}; 
+// two people joined:
+people += 2; 
+// people is now 2
+// let's add 3 eggs per person
+eggs += 3 * people;
+// eggs is now 6
+```
+Vairables `people` & `eggs` are initialized to `0`.
+Then, we add integer value `2` over the existing value `0` of the variable `people` and assigne it back to `people`.
+`people` becomes `2` now.
+Later, we add `3` eggs for each person, which turns out to be `6` eggs in total.
+Now add this `6` to existing value `0` of the variable `eggs` and assigne it back to `eggs`.
+`eggs` will be `6` now.
+The equivalent expression would be `people = people + 2` and `eggs = eggs + (3 * people)`.
+
 ~~~~exercism/advanced
 ## Casting
+
 Casting is the conversion from one type to another.
 If a `double` is needed, an `int` can be used in its place.
 The `5.0 / 2` example from above is handled by an implicit cast of `2` to `2.0`.

exercises/concept/freelancer-rates/.docs/introduction.md

@@ -1,14 +1,10 @@
 # Introduction
-
-## Numbers
-
 The built-in number types in C++ can be divided into integers and floating points.
 Integers are whole numbers like `0`, `691`, or `-2`.
 Floating point numbers are numbers with a decimal point like `6.02214076`, `0.1`, or `-1.616`.
 
-### Integers
-
-The following example shows the declaration and initialization of four different variables:
+## Integers
+The following example shows the declaration and initialization of four different variables 
 
 ```cpp
 int m_morales{9241};              // base 10: 0-9
@@ -17,7 +13,6 @@ int m_gargan{0b10010000011001};   // base  2: 0-1
 int b_reilly{022031};             // base  8: 0-7
                                   // Leading with a 0 not the letter o.
 ```
-
 When you assign a value to an `int` variable, you can do so directly with a literal.
 A literal is a hard-coded number like `9241`.
 There are different integer literals for several bases of the representation.
@@ -31,13 +26,13 @@ For more details on the different representation systems, take a look at [a smal
 You can use an apostrophe to separate digits for easier readability.
 `9'241` is the same as `0b0100'100'0001'1001` or `92'4'1`.
 
-### Floating-Point Numbers
+## Floating-Point Numbers
 
-The floating-point literals come in two flavors.
+The floating-point literals come in two flavors. 
 In addition to the intuitive `0.0024` it is possible to use its scientific notation `2.4e-3`.
 The most common floating-point type is `double`.
 
-### Arithmetic
+## Arithmetic
 
 C++ supports `+`, `-`, `*`, `/`, `(` and `)` and `%` to form expressions.
 The result from the operation between two integers is also an integer.
@@ -46,4 +41,44 @@ When one of the involved types is a floating-point type, the result will also be
 `5.0 / 2` and `5 / 2.0` will return `2.5`.
 `%` is the remainder operator and will return the remainder of an integer division: `5%3` is `2`.
 
-[cpp_numerical_bases]: https://cplusplus.com/doc/hex/
+## Assignment operator
+
+The assignment operator assigns a variable with a literal.
+Always takes place from right to left, and never the other way around.
+
+```cpp
+int length = 5;
+int width = 2;
+length = width;
+```
+Here integer value `5` is assigned to the variable `length`.
+Then integer value `2` is assigned to variable `width`.
+Finally value of `width` is copied to the variable `length` and the earlier value `5` will be lost.
+Consider also that we are only assigning the value of `width` to `length` at the moment of the assignment operation.
+Therefore, if the value of `width` changes at a later moment, it will not affect the value taken by `length`.
+
+Assignment operator can be combined with the other operators(arithmetic & bitwise) known as `compound assignment` operators `+=`, `-=`, `*=`, `/=`, `%=`.
+These operators modifies the current value of a variable by performing an operation on it.
+
+```cpp
+// we start with 0 people
+int people{};
+// we need 0 eggs
+int eggs{}; 
+// two people joined:
+people += 2; 
+// people is now 2
+// let's add 3 eggs per person
+eggs += 3 * people;
+// eggs is now 6
+```
+Vairables `people` & `eggs` are initialized to `0`.
+Then, we add integer value `2` over the existing value `0` of the variable `people` and assigne it back to `people`.
+`people` becomes `2` now.
+Later, we add `3` eggs for each person, which turns out to be `6` eggs in total.
+Now add this `6` to existing value `0` of the variable `eggs` and assigne it back to `eggs`.
+`eggs` will be `6` now.
+The equivalent expression would be `people = people + 2` and `eggs = eggs + (3 * people)` 
+
+
+[cpp_numerical_bases]: https://cplusplus.com/doc/hex/