Update doc/user_guide/checkers/extensions.rst

Co-authored-by: Morwenn <[email protected]>

Author: Pierre-Sassoulas

doc/user_guide/checkers/extensions.rst

@@ -89,9 +89,9 @@ Code Style checker Messages
   readability (it's also faster as it avoids an internal exec call). Disabled
   by default!
 :consider-math-not-float (R6106): *Consider %smath.%s instead of %s*
-  Using math.inf or math.nan permits to benefit from typing and it is 4 time
+  Using math.inf or math.nan permits to benefit from typing and it is up to 4 times
   faster than a float call (after the initial import of math). This check also
-  catch typo in float calls as a side effect.
+  catches typos in float calls as a side effect.
 
 
 .. _pylint.extensions.comparison_placement: