2 files changed, 31 insertions, 2 deletions
diff --git a/src/main/java/sevenUnits/unit/LinearUnit.java b/src/main/java/sevenUnits/unit/LinearUnit.java
index 3c3703c..d453a43 100644
--- a/src/main/java/sevenUnits/unit/LinearUnit.java
+++ b/src/main/java/sevenUnits/unit/LinearUnit.java
@@ -227,6 +227,19 @@ public final class LinearUnit extends Unit {
 			return false;
 		final LinearUnit other = (LinearUnit) obj;
 		return Objects.equals(this.getBase(), other.getBase())
+				&& Double.compare(this.getConversionFactor(),
+						other.getConversionFactor()) == 0;
+	}
+
+	/**
+	 * @return true iff this unit and other are equal,
+	 * ignoring small differences caused by floating-point error.
+	 * 
+	 * @apiNote This method is not transitive,
+	 * so it cannot be used as an equals method.
+	 */
+	public boolean equalsApproximately(final LinearUnit other) {
+		return Objects.equals(this.getBase(), other.getBase())
 				&& DecimalComparison.equals(this.getConversionFactor(),
 						other.getConversionFactor());
 	}
@@ -247,7 +260,7 @@ public final class LinearUnit extends Unit {
 	@Override
 	public int hashCode() {
 		return 31 * this.getBase().hashCode()
-				+ DecimalComparison.hash(this.getConversionFactor());
+				+ Double.hashCode(this.getConversionFactor());
 	}
 	
 	/**
diff --git a/src/main/java/sevenUnits/unit/UnitPrefix.java b/src/main/java/sevenUnits/unit/UnitPrefix.java
index 9035969..ec4be48 100644
--- a/src/main/java/sevenUnits/unit/UnitPrefix.java
+++ b/src/main/java/sevenUnits/unit/UnitPrefix.java
@@ -119,6 +119,22 @@ public final class UnitPrefix implements Nameable {
 		if (!(obj instanceof UnitPrefix))
 			return false;
 		final UnitPrefix other = (UnitPrefix) obj;
+		return Double.compare(this.getMultiplier(),
+				other.getMultiplier()) == 0;
+	}
+
+	/**
+	 * @return true iff this prefix and other are equal,
+	 * ignoring small differences caused by floating-point error.
+	 * 
+	 * @apiNote This method is not transitive,
+	 * so it cannot be used as an equals method.
+	 */
+	public boolean equalsApproximately(final UnitPrefix other) {
+		if (this == other)
+			return true;
+		if (other == null)
+			return false;
 		return DecimalComparison.equals(this.getMultiplier(),
 				other.getMultiplier());
 	}
@@ -143,7 +159,7 @@ public final class UnitPrefix implements Nameable {
 	 */
 	@Override
 	public int hashCode() {
-		return DecimalComparison.hash(this.getMultiplier());
+		return Double.hashCode(this.getMultiplier());
 	}
 
 	/**