How do you do addition fast?

To add quickly, practice mental math techniques such as breaking numbers into smaller, easier-to-add parts or using the "rounding and adjusting" method. For example, when adding 47 and 36, round 47 to 50, add 50 and 36 to get 86, and then subtract the 3 you added to reach 50, resulting in 83. Regular practice with flashcards or timed quizzes can also improve speed and accuracy. Additionally, using tools like the number line or visual aids can help reinforce quick addition skills.