docs: improve math/base/ops README.md examples

PR-URL: #1722
Closes: #1569 

---------

Signed-off-by: Philipp Burckhardt <pburckhardt@outlook.com>
Co-authored-by: Philipp Burckhardt <pburckhardt@outlook.com>
Reviewed-by: Philipp Burckhardt <pburckhardt@outlook.com>

Author: EuniceSim142

lib/node_modules/@stdlib/math/base/ops/README.md

@@ -87,10 +87,43 @@ The namespace contains the following functions:
 <!-- eslint no-undef: "error" -->
 
 ```javascript
-var objectKeys = require( '@stdlib/utils/keys' );
+var Complex128 = require( '@stdlib/complex/float64' );
 var ns = require( '@stdlib/math/base/ops' );
 
-console.log( objectKeys( ns ) );
+// Operations for double-precision floating point numbers:
+console.log( ns.add( 1.25, 0.45 ) );
+// => 1.7
+
+console.log( ns.sub( 1.25, 0.45 ) );
+// => 0.8
+
+// Operations for single-precision floating point numbers:
+console.log( ns.mulf( 1.3, 1.2 ) );
+// => ~1.56
+
+console.log( ns.divf( 1.2, 0.4 ) );
+// => 3.0
+
+// Operations for complex numbers:
+var z1 = new Complex128( 5.0, 3.0 );
+var z2 = new Complex128( -2.0, 1.0 );
+console.log( ns.cmul( z1, z2 ) ); // { 're': -13.0, 'im': -1.0 }
+// => <Complex128>
+
+// Operations for signed 32-bit integers:
+// 2^30 * -5 = -5368709120 => 32-bit integer overflow
+console.log( ns.imul( 1073741824|0, -5|0 ) );
+// => -1073741824
+
+// Operations for unsigned 32-bit integers:
+// 2^31 * 5 = 10737418240 => 32-bit integer overflow
+console.log( ns.umul( 2147483648>>>0, 5>>>0 ) );
+// => 2147483648
+
+// Operations for double word product:
+// -(2^31) * 2^30 = -2305843009213694000 => 32-bit integer overflow
+console.log( ns.imuldw( 0x80000000|0, 0x40000000|0 ) );
+// => [ -536870912, 0 ]
 ```
 
 </section>

lib/node_modules/@stdlib/math/base/ops/examples/index.js

@@ -18,7 +18,40 @@
 
 'use strict';
 
-var objectKeys = require( '@stdlib/utils/keys' );
+var Complex128 = require( '@stdlib/complex/float64' );
 var ns = require( './../lib' );
 
-console.log( objectKeys( ns ) );
+// Operations for double-precision floating point numbers:
+console.log( ns.add( 1.25, 0.45 ) );
+// => 1.7
+
+console.log( ns.sub( 1.25, 0.45 ) );
+// => 0.8
+
+// Operations for single-precision floating point numbers:
+console.log( ns.mulf( 1.3, 1.2 ) );
+// => ~1.56
+
+console.log( ns.divf( 1.2, 0.4 ) );
+// => 3.0
+
+// Operations for complex numbers:
+var z1 = new Complex128( 5.0, 3.0 );
+var z2 = new Complex128( -2.0, 1.0 );
+console.log( ns.cmul( z1, z2 ) ); // {'re': -13.0, 'im': -1.0 }
+// => <Complex128>
+
+// Operations for signed 32-bit integers:
+// 2^30 * -5 = -5368709120 => 32-bit integer overflow
+console.log( ns.imul( 1073741824|0, -5|0 ) );
+// => -1073741824
+
+// Operations for unsigned 32-bit integers:
+// 2^31 * 5 = 10737418240 => 32-bit integer overflow
+console.log( ns.umul( 2147483648>>>0, 5>>>0 ) );
+// => 2147483648
+
+// Operations for couble word product:
+// -(2^31) * 2^30 = -2305843009213694000 => 32-bit integer overflow
+console.log( ns.imuldw( 0x80000000|0, 0x40000000|0 ) );
+// => [ -536870912, 0 ]