Add a way to get a value of a primitive number to the Number interface.

src/org/nwapw/abacus/number/NaiveNumber.java

@@ -37,4 +37,24 @@ public class NaiveNumber implements Number {
     public Number negate() {
         return new NaiveNumber(-value);
     }
+
+    @Override
+    public Number zero() {
+        return new NaiveNumber(0);
+    }
+
+    @Override
+    public Number one() {
+        return new NaiveNumber(1);
+    }
+
+    @Override
+    public Number valueOf(int val) {
+        return new NaiveNumber(value);
+    }
+
+    @Override
+    public Number valueOf(double val) {
+        return new NaiveNumber(value);
+    }
 }

src/org/nwapw/abacus/number/Number.java

@@ -9,4 +9,10 @@ public interface Number {
     Number subtract(Number subtrahend);
     Number negate();
 
+    Number zero();
+    Number one();
+
+    Number valueOf(int val);
+    Number valueOf(double val);
+
 }