add structure

lib/widget/number_cell.dart

@@ -0,0 +1,20 @@
+import 'package:flutter/cupertino.dart';
+import 'package:intl/intl.dart';
+import 'package:fcs/theme/theme.dart' as theme;
+
+class NumberCell extends StatelessWidget {
+  final int number;
+  final numberFormatter;
+  final TextStyle textStyle;
+
+  NumberCell(this.number, {Key key, this.textStyle})
+      : numberFormatter = new NumberFormat("#,###"),
+        super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return new Text(
+        this.number == null ? '0' : numberFormatter.format(this.number),
+        style: textStyle == null ? theme.textStyle : textStyle);
+  }
+}