number: fix typo

Change-Id: Iee2b9cd52e9bc147ae595cb4d50f5096afaa3492
GitHub-Last-Rev: 922e349cdc4378ba52a15b395bf614b71246a7a3
GitHub-Pull-Request: golang/text#14
Reviewed-on: https://go-review.googlesource.com/c/text/+/231121
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
diff --git a/number/format.go b/number/format.go
index 1c3d41b..f2bdfdc 100644
--- a/number/format.go
+++ b/number/format.go
@@ -14,7 +14,7 @@
 	"golang.org/x/text/language"
 )
 
-// A FormatFunc formates a number.
+// A FormatFunc formats a number.
 type FormatFunc func(x interface{}, opts ...Option) Formatter
 
 // NewFormat creates a FormatFunc based on another FormatFunc and new options.