diff --git a/src/main/java/org/solovyev/android/calculator/TextHighlighter.java b/src/main/java/org/solovyev/android/calculator/TextHighlighter.java
index f99d7182..1dd1c6f2 100644
--- a/src/main/java/org/solovyev/android/calculator/TextHighlighter.java
+++ b/src/main/java/org/solovyev/android/calculator/TextHighlighter.java
@@ -139,7 +139,11 @@ public class TextHighlighter implements TextProcessor<TextHighlighter.Result> {
 
 	private int processHighlightedText(@NotNull StringBuilder result, int i, @NotNull String functionName, @NotNull String tag) {
 		result.append("<").append(tag).append(">").append(functionName).append("</").append(tag).append(">");
-		return i + functionName.length() - 1;
+		if (functionName.length() > 1) {
+			return i + functionName.length() - 1;
+		} else {
+			return i;
+		}
 	}
 
 	private int processBracketGroup(@NotNull StringBuilder result, @NotNull String s, int i, int numberOfOpenings, int maxNumberOfGroups) {
diff --git a/src/main/java/org/solovyev/android/calculator/math/MathType.java b/src/main/java/org/solovyev/android/calculator/math/MathType.java
index 3437982a..43e41157 100644
--- a/src/main/java/org/solovyev/android/calculator/math/MathType.java
+++ b/src/main/java/org/solovyev/android/calculator/math/MathType.java
@@ -36,6 +36,18 @@ public enum MathType {
 		}
 	},
 
+	grouping_separator(250, false, false, "'", " ") {
+		@Override
+		public int processToJscl(@NotNull StringBuilder result, int i, @NotNull String match) {
+			return i;
+		}
+
+		@Override
+		public int processFromJscl(@NotNull StringBuilder result, int i, @NotNull String match) {
+			return i;
+		}
+	},
+
 	power_10(300, true, false, "E") {
 		@Override
 		protected String getSubstituteToJscl(@NotNull String match) {
diff --git a/src/main/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessor.java b/src/main/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessor.java
index 5daf6e38..93077fc4 100644
--- a/src/main/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessor.java
+++ b/src/main/java/org/solovyev/android/calculator/model/FromJsclSimplifyTextProcessor.java
@@ -22,9 +22,6 @@ public class FromJsclSimplifyTextProcessor implements TextProcessor<String> {
 		final NumberBuilder numberBuilder = new NumberBuilder();
 		for (int i = 0; i < s.length(); i++) {
 			char ch = s.charAt(i);
-			if ( Character.isWhitespace(ch) ) {
-				continue;
-			}
 
 			MathType.Result mathTypeResult = MathType.getType(s, i);
 
diff --git a/src/main/java/org/solovyev/android/calculator/model/NumberBuilder.java b/src/main/java/org/solovyev/android/calculator/model/NumberBuilder.java
index 24e7d82c..eaa298fa 100644
--- a/src/main/java/org/solovyev/android/calculator/model/NumberBuilder.java
+++ b/src/main/java/org/solovyev/android/calculator/model/NumberBuilder.java
@@ -30,13 +30,14 @@ public class NumberBuilder {
 		number = null;
 
 		final MathType.Result possibleResult;
-		if (mathTypeResult.getMathType() == MathType.digit || mathTypeResult.getMathType() == MathType.dot || mathTypeResult.getMathType() == MathType.power_10) {
+		if (CollectionsUtils.contains(mathTypeResult.getMathType(), MathType.digit, MathType.dot, MathType.grouping_separator, MathType.power_10)) {
 			if (numberBuilder == null) {
 				numberBuilder = new StringBuilder();
 			}
+
 			numberBuilder.append(mathTypeResult.getMatch());
 
-			possibleResult = replaceSystemVars(sb, number, numberOffset);
+			possibleResult = null;
 		} else {
 			possibleResult = process(sb, numberOffset);
 		}
@@ -47,9 +48,16 @@ public class NumberBuilder {
 
 	@Nullable
 	public MathType.Result process(@NotNull StringBuilder sb, @Nullable MutableObject<Integer> numberOffset) {
+		int numberOfGroupingSeparators = 0;
+
 		if (numberBuilder != null) {
 			try {
 				number = numberBuilder.toString();
+				for (String groupingSeparator : MathType.grouping_separator.getTokens()) {
+					String newNumber = number.replace(groupingSeparator, "");
+					numberOfGroupingSeparators += number.length() - newNumber.length();
+					number = newNumber;
+				}
 				Double.valueOf(number);
 			} catch (NumberFormatException e) {
 				number = null;
@@ -60,11 +68,11 @@ public class NumberBuilder {
 			number = null;
 		}
 
-		return replaceSystemVars(sb, number, numberOffset);
+		return replaceSystemVars(sb, number, numberOfGroupingSeparators, numberOffset);
 	}
 
 	@Nullable
-	private MathType.Result replaceSystemVars(StringBuilder sb, String number, @Nullable MutableObject<Integer> numberOffset) {
+	private MathType.Result replaceSystemVars(StringBuilder sb, String number, int numberOfGroupingSeparators, @Nullable MutableObject<Integer> numberOffset) {
 		MathType.Result result = null;
 
 		if (number != null) {
@@ -77,14 +85,14 @@ public class NumberBuilder {
 			});
 
 			if (var != null) {
-				sb.delete(sb.length() - number.length(), sb.length());
+				sb.delete(sb.length() - number.length() - numberOfGroupingSeparators, sb.length());
 				sb.append(var.getName());
 				result = new MathType.Result(MathType.constant, var.getName());
 			} else {
-				sb.delete(sb.length() - number.length(), sb.length());
+				sb.delete(sb.length() - number.length() - numberOfGroupingSeparators, sb.length());
 				final String formattedNumber = CalculatorEngine.instance.format(Double.valueOf(number));
 				if ( numberOffset != null ) {
-					numberOffset.setObject(formattedNumber.length() - number.length());
+					numberOffset.setObject(formattedNumber.length() - number.length() - numberOfGroupingSeparators);
 				}
 				sb.append(formattedNumber);
 			}
diff --git a/src/main/java/org/solovyev/android/calculator/model/ToJsclTextProcessor.java b/src/main/java/org/solovyev/android/calculator/model/ToJsclTextProcessor.java
index 1dda86d1..b9c9df67 100644
--- a/src/main/java/org/solovyev/android/calculator/model/ToJsclTextProcessor.java
+++ b/src/main/java/org/solovyev/android/calculator/model/ToJsclTextProcessor.java
@@ -33,10 +33,6 @@ class ToJsclTextProcessor implements TextProcessor<PreparedExpression> {
 		for (int i = 0; i < s.length(); i++) {
 			startsWithFinder.setI(i);
 
-			if ( Character.isWhitespace(s.charAt(i))) {
-				continue;
-			}
-
 			mathTypeBefore = mathTypeResult == null ? null : mathTypeResult.getMathType();
 
 			mathTypeResult = MathType.getType(s, i);
@@ -123,7 +119,7 @@ class ToJsclTextProcessor implements TextProcessor<PreparedExpression> {
 
 			final MathType mathType = MathType.getType(s, result).getMathType();
 
-			if (CollectionsUtils.contains(mathType, MathType.digit, MathType.dot)) {
+			if (CollectionsUtils.contains(mathType, MathType.digit, MathType.dot, MathType.grouping_separator)) {
 				// continue
 			} else if (mathType == MathType.close_group_symbol) {
 				numberOfOpenGroups++;