Fix typo

README.md

@@ -23,7 +23,7 @@ viewer.scalebar({
 });
 `````
 
-To change the Unit system from the defualt of Metric to Imperial, you must reference the `sizeAndTextRenderer` function in the library directly:
+To change the unit system from the default of Metric to Imperial, you must reference the `sizeAndTextRenderer` function in the library directly:
 
 `````javascript
 viewer.scalebar({
@@ -49,4 +49,4 @@ guarantees, expressed or implied, about its quality, reliability, or
 any other characteristic. We would appreciate acknowledgement if the
 software is used.
 
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+[![Gitter](https://badges.gitter.im/Join Chat.svg)](https://gitter.im/NIST-ISG/OpenSeadragonScalebar?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)