Flubaroo is one of my all-time favorite Google Sheets Add-ons (formerly scripts) because it enables me to save time on routine tasks like grading quizzes and move on to fun things like actually working with my students.
Flubaroo has a bunch of features that you can take advantage of once you know how they all work. Some of these features include grading ranges of numerical responses, creating case-sensitive answer keys, accepting multiple correct responses to questions, and automatically sending grades to students. The Flubaroo help center explains how to do all of those things and more.
Before your students take another quiz through Google Forms, take a few minutes to explore the uses of Flubaroo. You just might find yourself spending less time grading and more time doing the things that make teaching fun.