03_numberChecker: Fix grammar (#655)

Author: spidercam

foundations/03_numberChecker/README.md

@@ -4,7 +4,7 @@ Modify the code so it returns `true` when the number is greater than or equal to
 
 Currently, the code returns `true` if the number is `6`, otherwise, it returns `false`.
 
-You may also notice that in this exercise, there are multiple tests (in the file `numberChecker.spec.js`). Only the first test is currently enabled. So after making sure that the first test passes, enable the next one by deleting the `.skip` portion from the `test.skip()` function. It is usually easier if you enable only one test a time, then edit your code so that it passes. You can keep enabling only one at a time until slowly but surely, they all pass!
+You may also notice that in this exercise, there are multiple tests (in the file `numberChecker.spec.js`). Only the first test is currently enabled. So after making sure that the first test passes, enable the next one by deleting the `.skip` portion from the `test.skip()` function. It is usually easier if you enable only one test at a time, then edit your code so that it passes. You can keep enabling only one at a time until slowly but surely, they all pass!
 
 If running `npm test numberChecker.spec.js` returns results similar to what is shown below (showing some tests are skipped), make sure that you have enabled the rest of the tests, as described in the instructions above: