added placeholder for 'all' instruction page

lib/main.dart

@@ -12,6 +12,7 @@ import 'package:ohthatsa/pages/practice/instructions/MonthInstructionPage.dart';
 import 'package:ohthatsa/pages/practice/instructions/YearInstructionPage.dart';
 import 'package:ohthatsa/pages/practice/instructions/CenturyInstructionPage.dart';
 import 'package:ohthatsa/pages/practice/instructions/ModInstructionPage.dart';
+import 'package:ohthatsa/pages/practice/instructions/AllInstructionPage.dart';
 import 'package:rxdart/subjects.dart';
 import 'package:flutter/services.dart';
 
@@ -148,7 +149,7 @@ class RouteGenerator {
         return MaterialPageRoute(builder: (context) => ModInstructionPage());
       }
       case "/instructions/all": {
-        return MaterialPageRoute(builder: (context) => YearInstructionPage());
+        return MaterialPageRoute(builder: (context) => AllInstructionPage());
       }
       default: {
         return null;

lib/pages/practice/instructions/AllInstructionPage.dart

@@ -0,0 +1,70 @@
+import 'package:flutter/material.dart';
+import 'package:numberpicker/numberpicker.dart';
+import 'package:ohthatsa/other/AppDrawer.dart';
+import 'package:ohthatsa/util/DayCalculator.dart';
+import 'package:ohthatsa/util/Months.dart';
+
+class AllInstructionPage extends StatefulWidget {
+  @override
+  _AllInstructionPageState createState() => _AllInstructionPageState();
+}
+
+class _AllInstructionPageState extends State<AllInstructionPage> {
+
+  @override
+  void initState(){
+    super.initState();
+  }
+
+  static const textStyle = TextStyle(
+      fontSize: 20
+  );
+  static const textStyleU = TextStyle(
+      fontSize: 20,
+      decoration: TextDecoration.underline
+  );
+  static const valueStyle = TextStyle(
+      color: Colors.green,
+      fontSize: 20
+  );
+  @override
+  Widget build(BuildContext context){
+    return Scaffold(
+        drawer: AppDrawer(),
+        appBar: AppBar(
+            title: Text("All Instructions")
+        ),
+
+        body: Column(
+            children: <Widget>[
+              Container(
+                padding: EdgeInsets.fromLTRB(0, 50, 0, 10),
+                child:Column(
+                    mainAxisAlignment: MainAxisAlignment.center,
+                    children: <Widget>[
+                      Text("Modulus (Mod) is the remainder after dividing", style: textStyle),
+                      Row(
+                        mainAxisAlignment: MainAxisAlignment.center,
+                        children: <Widget>[
+                          Text("value.toString()", style: valueStyle),
+                          Text(" divided by 7 is " + "div.toString()", style: textStyle),
+                        ],
+                      ),
+                      Text("But that leaves " + "remainder.toString()" + " left over", style: textStyle),
+                      Row(
+                        mainAxisAlignment: MainAxisAlignment.center,
+                        children: <Widget>[
+                          Text("So the result of ", style: textStyle),
+                          Text("value.toString()", style: valueStyle),
+                          Text(" mod 7 is ", style: textStyle),
+                          Text("remainder.toString()", style: textStyleU),
+                        ],
+                      ),
+                    ]
+                ),
+              ),
+            ]
+        )
+    );
+  }
+}