This lesson is on the Least Common Multiple (LCM) and the Least Common Denominator (LCD). Knowing how to find the LCM/LCD is absolutely critical to your success with fractions. Many students can find the LCM/LCD when the numbers involved are easy. However, when the numbers in fractions are more difficult (larger) it’s easy for students to find themselves lost- make sure this is not you! Finding the LCM/LCD is part of adding and subtracting fractions so take your time and really master this very important skill.