During the first week of the second unit we dove right in and got started working with multiplication. We began to break down how difficult it is for students to solve multiplication or division problems when they don't even know the basics.
We started off by learning that if a student can understand the multiplication facts of 2's, 5's and 10's, they should then be able to solve any other problem with no problem. These are called Derived Facts. An example of this is...
This problem explains that if a student has the basics (2's, 5's, and 10's) memorized, then a problem of 9x3 (example) should not be hard. This picture shows the problem 9x3=?. To solve this, the student would understand that they are trying to figure out what 9 groups of 3's are or 3 groups of 9's. But, in this case we are using 9 groups of 3's.
The student then knows that since 10x3=30...which is 10 groups of 3's...so the next step is to take away one group of 3 to get to only 9 groups.
They successfully solved 10x3 which equals 30. So, they take away one group of 3, 30-3=? which equals 27. Therefore... 9x3=27!
This problem shows that the student understood their multiplication facts of 10's and then went from there to solve the problem correctly.
This week was very insightful! I learned that you have to start with the basics of multiplication and then work your way up. Sometimes I get flustered with solving difficult multiplication problems and I now know that it is ALWAYS okay to go back to where you started and go from there. I can't wait to know what we will learn next week!
