It is very important for students to understand the meaning behind multiplication. It is also important for them to master multiplication facts so that they may apply them to other types of math. They need to know the multiples of numbers to simplify fractions, solve large division problems, see patterns, understand algebra, and so much more.
Being fluent with Math is similar to being fluent in Reading. If a student knows his sight words and only has to sound out a few unfamiliar words he is able to read a paragraph or story fluently, and comprehend it. However, if he has to sound out all of the words as he reads, the paragraph or passage will take a long time and fluency will be weaker and comprehension compromised.