Input control to translate user value to model value.

<!DOCTYPE html>
<html>

  <head>
    <base href="." />
    <script type="text/javascript" charset="utf-8">
      window.AngularVersionForThisPlunker = 'latest'
    </script>
    <title>angular playground</title>
    <link rel="stylesheet" href="style.css" />
    <script src="https://unpkg.com/core-js@2.4.1/client/shim.min.js"></script>
    <script src="https://unpkg.com/zone.js/dist/zone.js"></script>
    <script src="https://unpkg.com/zone.js/dist/long-stack-trace-zone.js"></script>
    <script src="https://unpkg.com/reflect-metadata@0.1.3/Reflect.js"></script>
    <script src="https://unpkg.com/systemjs@0.19.31/dist/system.js"></script>
    <script src="config.js"></script>
    <script>
    System.import('app')
      .catch(console.error.bind(console));
  </script>
  </head>

  <body>
    <my-app>
    loading...
  </my-app>
  </body>

</html>

/* Styles go here */

.box{
  height: 200px; 
  border: 1px solid red; 
  overflow:scroll;
}

### Angular Starter Plunker - Typescript

var angularVersion;
if(window.AngularVersionForThisPlunker === 'latest'){
  angularVersion = ''; //picks up latest
}
else {
  angularVersion = '@' + window.AngularVersionForThisPlunker;
}

System.config({
  //use typescript for compilation
  transpiler: 'typescript',
  //typescript compiler options
  typescriptOptions: {
    emitDecoratorMetadata: true
  },
  paths: {
    'npm:': 'https://unpkg.com/'
  },
  //map tells the System loader where to look for things
  map: {
    
    'app': './src',
    '@angular/core': 'npm:@angular/core'+ angularVersion + '/bundles/core.umd.js',
    '@angular/common': 'npm:@angular/common' + angularVersion + '/bundles/common.umd.js',
    '@angular/compiler': 'npm:@angular/compiler' + angularVersion  + '/bundles/compiler.umd.js',
    '@angular/platform-browser': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser.umd.js',
    '@angular/platform-browser-dynamic': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic.umd.js',
    '@angular/http': 'npm:@angular/http' + angularVersion + '/bundles/http.umd.js',
    '@angular/router': 'npm:@angular/router' + angularVersion +'/bundles/router.umd.js',
    '@angular/forms': 'npm:@angular/forms' + angularVersion + '/bundles/forms.umd.js',
    '@angular/animations': 'npm:@angular/animations' + angularVersion + '/bundles/animations.umd.js',
    '@angular/platform-browser/animations': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-animations.umd.js',
    '@angular/animations/browser': 'npm:@angular/animations' + angularVersion + '/bundles/animations-browser.umd.js',
    
    '@angular/core/testing': 'npm:@angular/core' + angularVersion + '/bundles/core-testing.umd.js',
    '@angular/common/testing': 'npm:@angular/common' + angularVersion + '/bundles/common-testing.umd.js',
    '@angular/compiler/testing': 'npm:@angular/compiler' + angularVersion + '/bundles/compiler-testing.umd.js',
    '@angular/platform-browser/testing': 'npm:@angular/platform-browser' + angularVersion + '/bundles/platform-browser-testing.umd.js',
    '@angular/platform-browser-dynamic/testing': 'npm:@angular/platform-browser-dynamic' + angularVersion + '/bundles/platform-browser-dynamic-testing.umd.js',
    '@angular/http/testing': 'npm:@angular/http' + angularVersion + '/bundles/http-testing.umd.js',
    '@angular/router/testing': 'npm:@angular/router' + angularVersion + '/bundles/router-testing.umd.js',
    'tslib': 'npm:tslib@1.6.1',
    'rxjs': 'npm:rxjs',
    'typescript': 'npm:typescript@2.2.1/lib/typescript.js'
  },
  //packages defines our app package
  packages: {
    app: {
      main: './main.ts',
      defaultExtension: 'ts'
    },
    rxjs: {
      defaultExtension: 'js'
    }
  }
});

//main entry point
import {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
import {AppModule} from './app.module';

platformBrowserDynamic().bootstrapModule(AppModule)

//our root app component
import {Component, VERSION} from '@angular/core'

@Component({
  selector: 'my-app',
  templateUrl: 'src/app.component.html'
})
export class AppComponent {
  
  // Set the model value
  myValue = 1;
}

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { CommonModule } from "@angular/common";
import { HttpModule, Http } from "@angular/http";
import { FormsModule, ReactiveFormsModule } from "@angular/forms";

import {AppComponent} from './app.component';
import {PercentComponent} from './percent.component';

@NgModule({
  imports: [ 
    BrowserModule,
    CommonModule,
    HttpModule,
    FormsModule,
    ReactiveFormsModule
  ],
  declarations: [ AppComponent, PercentComponent ],
  bootstrap: [ AppComponent ]
})
export class AppModule {}

<percent-input [(ngModel)]="myValue"></percent-input>
<br/>
<span>Form Value {{myValue}}</span>

<div>
  <input 
    #percentInput
    type="number" 
    [disabled]="disabled"
    [attr.disabled]="disabled"
    class="form-control"       
    [(ngModel)]="wholeNumber"
    (keydown)="onKeyDown($event)"
    min="0" 
    max="100" 
    step="1" />
    <br/>
    <span>Control Value {{value}}</span>
    <br/>
    <span>Inner Value {{percent}}</span>
    <br/>
    <span>Formatted Value {{wholeNumber}}</span>
</div>

// -----------------------------------------------------------------------
// <copyright file="precent.component.ts" company="">
// </copyright>
// <summary>
// Defines the percent component, wraps the input control to handle all the percent conversion
// </summary>
// -----------------------------------------------------------------------

// Import the angular modules
import { Component, ViewChild } from "@angular/core";
import { ControlValueAccessor, NG_VALUE_ACCESSOR } from "@angular/forms";

// <summary>
// Enumeration of keyboard key codes
// </summary>
enum KeyCode {
    E = 69,
    Add = 107,
    Subtract = 109,
    DecimalPoint = 110,
    Dash = 189,
    Period = 190,
}

@Component({
    selector: "percent-input",
    templateUrl: "./src/percent.component.html",
    providers: [
        {
            provide: NG_VALUE_ACCESSOR,
            useExisting: PercentComponent,
            multi: true
        }
    ]
})

export class PercentComponent implements ControlValueAccessor {

    // <summary>
    // Internal value of the percent component
    // </summary>
    percent: number;
    
    // <summary>
    // Internal minimum value
    // </summary>
    minValue = 0;
    
    // <summary>
    // Internal maximum value
    // </summary>
    maxValue = 100;
    
    // <summary>
    // Reference to the value propage change function
    // </summary>
    propagateChange = (_: any) => { };

      // <summary>
    // Change event when the map view has been changed
    // </summary>
    @ViewChild("percentInput") inputControl;

    // <summary>
    // Get and set the control formated value for display
    // </summary>
    get wholeNumber(): number {
        // Null check
        if (this.percent == null) {
            return null;
        }

        return Math.round(this.percent * 100);
    }
    set wholeNumber(v: number) {

        // Null check
        if (v != null) {
          if(v >= this.minValue && v <= this.maxValue) {
           
           this.percent = Number((v / 100).toFixed(2));
          }else{
            this.inputControl.nativeElement.value = this.wholeNumber;
          }
        } else {
            this.percent = v;
        }

        // Call the propage change function
        this.propagateChange(this.percent);
    }

    // <summary>
    // Control get value accessor
    // </summary>
    // get accessor
    get value(): number {
        return this.percent;
    }

    // <summary>
    // Control set value accessor
    // </summary>
    set value(v: number) {
        this.percent = v;

        // Call the propage change function
        this.propagateChange(this.percent);
    }
    
    // <summary>
    // Onkey down event handler
    // </summary>
    onKeyDown(event){
      
      // Prevent the following keys
      if(event.keyCode === KeyCode.Period || 
        event.keyCode === KeyCode.DecimalPoint || 
        event.keyCode === KeyCode.E ||
        event.keyCode === KeyCode.Add ||
        event.keyCode === KeyCode.Dash ||
        event.keyCode === KeyCode.Subtract){
        event.preventDefault();
      }
    }
    
    // <summary>
    // Control write value
    // </summary>
    writeValue(v: number) {
        // If the model is cleared, we want the look up control to reset the values to empty
        if (v == null) {
            v = null;
        }

        this.percent = v;
    }

    // <summary>
    // Control register on change function
    // </summary>
    registerOnChange(fn) {
        this.propagateChange = fn;
    }

    // <summary>
    // Control register on touch function
    // </summary>
    registerOnTouched() {
    }
}