diff --git a/core/src/main/java/org/nwapw/abacus/number/NumberInterface.java b/core/src/main/kotlin/org/nwapw/abacus/number/NumberInterface.kt
old mode 100755
new mode 100644
similarity index 64%
rename from core/src/main/java/org/nwapw/abacus/number/NumberInterface.java
rename to core/src/main/kotlin/org/nwapw/abacus/number/NumberInterface.kt
index bcccddb..c3f4d90
--- a/core/src/main/java/org/nwapw/abacus/number/NumberInterface.java
+++ b/core/src/main/kotlin/org/nwapw/abacus/number/NumberInterface.kt
@@ -1,253 +1,233 @@
-package org.nwapw.abacus.number;
-
-import org.nwapw.abacus.exception.ComputationInterruptedException;
-
-/**
- * An interface used to represent a number.
- */
-public abstract class NumberInterface implements Comparable<NumberInterface> {
-
-    /**
-     * Check if the thread was interrupted and
-     * throw an exception to end the computation.
-     */
-    private static void checkInterrupted() {
-        if (Thread.currentThread().isInterrupted())
-            throw new ComputationInterruptedException();
-    }
-
-    /**
-     * The maximum precision to which this number operates.
-     *
-     * @return the precision.
-     */
-    public abstract int getMaxPrecision();
-
-    /**
-     * Multiplies this number by another, returning
-     * a new number instance.
-     *
-     * @param multiplier the multiplier
-     * @return the result of the multiplication.
-     */
-    protected abstract NumberInterface multiplyInternal(NumberInterface multiplier);
-
-    /**
-     * Multiplies this number by another, returning
-     * a new number instance. Also, checks if the
-     * thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @param multiplier the multiplier
-     * @return the result of the multiplication.
-     */
-    public final NumberInterface multiply(NumberInterface multiplier) {
-        checkInterrupted();
-        return multiplyInternal(multiplier);
-    }
-
-    /**
-     * Divides this number by another, returning
-     * a new number instance.
-     *
-     * @param divisor the divisor
-     * @return the result of the division.
-     */
-    protected abstract NumberInterface divideInternal(NumberInterface divisor);
-
-    /**
-     * Divides this number by another, returning
-     * a new number instance. Also, checks if the
-     * thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @param divisor the divisor
-     * @return the result of the division.
-     */
-    public final NumberInterface divide(NumberInterface divisor) {
-        checkInterrupted();
-        return divideInternal(divisor);
-    }
-
-    /**
-     * Adds this number to another, returning
-     * a new number instance.
-     *
-     * @param summand the summand
-     * @return the result of the summation.
-     */
-    protected abstract NumberInterface addInternal(NumberInterface summand);
-
-    /**
-     * Adds this number to another, returning
-     * a new number instance. Also, checks if the
-     * thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @param summand the summand
-     * @return the result of the summation.
-     */
-    public final NumberInterface add(NumberInterface summand) {
-        checkInterrupted();
-        return addInternal(summand);
-    }
-
-    /**
-     * Subtracts another number from this number,
-     * a new number instance.
-     *
-     * @param subtrahend the subtrahend.
-     * @return the result of the subtraction.
-     */
-    protected abstract NumberInterface subtractInternal(NumberInterface subtrahend);
-
-    /**
-     * Subtracts another number from this number,
-     * a new number instance. Also, checks if the
-     * thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @param subtrahend the subtrahend.
-     * @return the result of the subtraction.
-     */
-    public final NumberInterface subtract(NumberInterface subtrahend) {
-        checkInterrupted();
-        return subtractInternal(subtrahend);
-    }
-
-    /**
-     * Returns a new instance of this number with
-     * the sign flipped.
-     *
-     * @return the new instance.
-     */
-    protected abstract NumberInterface negateInternal();
-
-
-    /**
-     * Returns a new instance of this number with
-     * the sign flipped. Also, checks if the
-     * thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @return the new instance.
-     */
-    public final NumberInterface negate() {
-        checkInterrupted();
-        return negateInternal();
-    }
-
-    /**
-     * Raises this number to an integer power.
-     *
-     * @param exponent the exponent to which to take the number.
-     * @return the resulting value.
-     */
-    protected abstract NumberInterface intPowInternal(int exponent);
-
-    /**
-     * Raises this number to an integer power. Also, checks if the
-     * thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @param exponent the exponent to which to take the number.
-     * @return the resulting value.
-     */
-    public final NumberInterface intPow(int exponent) {
-        checkInterrupted();
-        return intPowInternal(exponent);
-    }
-
-    /**
-     * Same as Math.signum().
-     *
-     * @return 1 if this number is positive, -1 if this number is negative, 0 if this number is 0.
-     */
-    public abstract int signum();
-
-    /**
-     * Returns the least integer greater than or equal to the number.
-     *
-     * @return the least integer greater or equal to the number, if int can hold the value.
-     */
-    protected abstract NumberInterface ceilingInternal();
-
-    /**
-     * Returns the least integer greater than or equal to the number.
-     * Also, checks if the thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @return the least integer bigger or equal to the number.
-     */
-    public final NumberInterface ceiling() {
-        checkInterrupted();
-        return ceilingInternal();
-    }
-
-    /**
-     * Return the greatest integer less than or equal to the number.
-     *
-     * @return the greatest integer smaller or equal the number.
-     */
-    protected abstract NumberInterface floorInternal();
-
-    /**
-     * Return the greatest integer less than or equal to the number.
-     * Also, checks if the thread has been interrupted, and if so, throws
-     * an exception.
-     *
-     * @return the greatest int smaller than or equal to the number.
-     */
-    public final NumberInterface floor() {
-        checkInterrupted();
-        return floorInternal();
-    }
-
-    /**
-     * Returns the fractional part of the number.
-     *
-     * @return the fractional part of the number.
-     */
-    protected abstract NumberInterface fractionalPartInternal();
-
-    /**
-     * Returns the fractional part of the number, specifically x - floor(x).
-     * Also, checks if the thread has been interrupted,
-     * and if so, throws an exception.
-     *
-     * @return the fractional part of the number.
-     */
-    public final NumberInterface fractionalPart() {
-        checkInterrupted();
-        return fractionalPartInternal();
-    }
-
-    /**
-     * Returns the integer representation of this number, discarding any fractional part,
-     * if int can hold the value.
-     *
-     * @return the integer value of this number.
-     */
-    public abstract int intValue();
-
-    /**
-     * Returns the smallest error this instance can tolerate depending
-     * on its precision and value.
-     *
-     * @return the smallest error that should be permitted in calculations.
-     */
-    public abstract NumberInterface getMaxError();
-
-    /**
-     * Returns a NumberRangeBuilder object, which is used to create a range.
-     * The reason that this returns a builder and not an actual range is that
-     * the NumberRange needs to promote values passed to it, which
-     * requires an abacus instance.
-     * @param other the value at the bottom of the range.
-     * @return the resulting range builder.
-     */
-    public NumberRangeBuilder rangeTo(NumberInterface other){
-        return new NumberRangeBuilder(this, other);
-    }
-
-}
+package org.nwapw.abacus.number
+
+import org.nwapw.abacus.exception.ComputationInterruptedException
+
+abstract class NumberInterface: Comparable<NumberInterface> {
+
+    /**
+     * Check if the thread was interrupted and
+     * throw an exception to end the computation.
+     */
+    private fun checkInterrupted(){
+        if(Thread.currentThread().isInterrupted)
+            throw ComputationInterruptedException()
+    }
+
+    /**
+     * Returns the integer representation of this number, discarding any fractional part,
+     * if int can hold the value.
+     *
+     * @return the integer value of this number.
+     */
+    abstract fun intValue(): Int
+    /**
+     * Same as Math.signum().
+     *
+     * @return 1 if this number is positive, -1 if this number is negative, 0 if this number is 0.
+     */
+    abstract fun signum(): Int
+
+    /**
+     * The maximum precision to which this number operates.
+     */
+    abstract val maxPrecision: Int
+    /**
+     * Returns the smallest error this instance can tolerate depending
+     * on its precision and value.
+     */
+    abstract val maxError: NumberInterface
+
+    /**
+     * Adds this number to another, returning
+     * a new number instance.
+     *
+     * @param summand the summand
+     * @return the result of the summation.
+     */
+    abstract fun addInternal(summand: NumberInterface): NumberInterface
+    /**
+     * Subtracts another number from this number,
+     * a new number instance.
+     *
+     * @param subtrahend the subtrahend.
+     * @return the result of the subtraction.
+     */
+    abstract fun subtractInternal(subtrahend: NumberInterface): NumberInterface
+    /**
+     * Multiplies this number by another, returning
+     * a new number instance.
+     *
+     * @param multiplier the multiplier
+     * @return the result of the multiplication.
+     */
+    abstract fun multiplyInternal(multiplier: NumberInterface): NumberInterface
+    /**
+     * Divides this number by another, returning
+     * a new number instance.
+     *
+     * @param divisor the divisor
+     * @return the result of the division.
+     */
+    abstract fun divideInternal(divisor: NumberInterface): NumberInterface
+    /**
+     * Returns a new instance of this number with
+     * the sign flipped.
+     *
+     * @return the new instance.
+     */
+    abstract fun negateInternal(): NumberInterface
+    /**
+     * Raises this number to an integer power.
+     *
+     * @param exponent the exponent to which to take the number.
+     * @return the resulting value.
+     */
+    abstract fun intPowInternal(pow: Int): NumberInterface
+    /**
+     * Returns the least integer greater than or equal to the number.
+     *
+     * @return the least integer greater or equal to the number, if int can hold the value.
+     */
+    abstract fun ceilingInternal(): NumberInterface
+    /**
+     * Return the greatest integer less than or equal to the number.
+     *
+     * @return the greatest integer smaller or equal the number.
+     */
+    abstract fun floorInternal(): NumberInterface
+    /**
+     * Returns the fractional part of the number.
+     *
+     * @return the fractional part of the number.
+     */
+    abstract fun fractionalPartInternal(): NumberInterface
+
+    /**
+     * Adds this number to another, returning
+     * a new number instance. Also, checks if the
+     * thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @param summand the summand
+     * @return the result of the summation.
+     */
+    fun add(summand: NumberInterface): NumberInterface {
+        checkInterrupted()
+        return addInternal(summand)
+    }
+
+    /**
+     * Subtracts another number from this number,
+     * a new number instance. Also, checks if the
+     * thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @param subtrahend the subtrahend.
+     * @return the result of the subtraction.
+     */
+    fun subtract(subtrahend: NumberInterface): NumberInterface {
+        checkInterrupted()
+        return subtractInternal(subtrahend)
+    }
+
+    /**
+     * Multiplies this number by another, returning
+     * a new number instance. Also, checks if the
+     * thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @param multiplier the multiplier
+     * @return the result of the multiplication.
+     */
+    fun multiply(multiplier: NumberInterface): NumberInterface {
+        checkInterrupted()
+        return multiplyInternal(multiplier)
+    }
+
+    /**
+     * Divides this number by another, returning
+     * a new number instance. Also, checks if the
+     * thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @param divisor the divisor
+     * @return the result of the division.
+     */
+    fun divide(divisor: NumberInterface): NumberInterface {
+        checkInterrupted()
+        return divideInternal(divisor)
+    }
+
+    /**
+     * Returns a new instance of this number with
+     * the sign flipped. Also, checks if the
+     * thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @return the new instance.
+     */
+    fun negate(): NumberInterface {
+        checkInterrupted()
+        return negateInternal()
+    }
+
+    /**
+     * Raises this number to an integer power. Also, checks if the
+     * thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @param exponent the exponent to which to take the number.
+     * @return the resulting value.
+     */
+    fun intPow(exponent: Int): NumberInterface {
+        checkInterrupted()
+        return intPowInternal(exponent)
+    }
+
+    /**
+     * Returns the least integer greater than or equal to the number.
+     * Also, checks if the thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @return the least integer bigger or equal to the number.
+     */
+    fun ceiling(): NumberInterface {
+        checkInterrupted()
+        return ceilingInternal()
+    }
+
+    /**
+     * Return the greatest integer less than or equal to the number.
+     * Also, checks if the thread has been interrupted, and if so, throws
+     * an exception.
+     *
+     * @return the greatest int smaller than or equal to the number.
+     */
+    fun floor(): NumberInterface {
+        checkInterrupted()
+        return floorInternal()
+    }
+
+    /**
+     * Returns the fractional part of the number, specifically x - floor(x).
+     * Also, checks if the thread has been interrupted,
+     * and if so, throws an exception.
+     *
+     * @return the fractional part of the number.
+     */
+    fun fractionalPart(): NumberInterface {
+        checkInterrupted()
+        return fractionalPartInternal()
+    }
+
+    /**
+     * Returns a NumberRangeBuilder object, which is used to create a range.
+     * The reason that this returns a builder and not an actual range is that
+     * the NumberRange needs to promote values passed to it, which
+     * requires an abacus instance.
+     * @param other the value at the bottom of the range.
+     * @return the resulting range builder.
+     */
+    operator fun rangeTo(other: NumberInterface) = NumberRangeBuilder(this, other)
+
+}
\ No newline at end of file