Room 207

Room 207
Yahoo! Here we go 4th graders!

Tuesday, January 13, 2015

Understanding 4th grade Multiplication

Multiplication today is different from the way that many adults learned it.  The focus is on a strong foundation of understanding place value.  Students learn how to "break apart" large numbers into more manageable numbers to multiply by.  For example, when multiplying 637 we divide it into hundreds, tens and ones as shown below.   This is the expanded form.

We also learn the traditional algorithm, but now the students understand the numbers that are carried.

When multiplying a 2-by-2 digit number, we break the numbers up first.  For example, 26 becomes 20 and 6 and 34 becomes 30 and 4. Then we draw "a box" and figure out the 4 equations that would multiply each number.  These are the partial products.  Finally, we add the partial products to find the final product.

Common fourth grade mistakes are:
        1. Creating the 4 correct equations.
        2. Basic multiplication fact errors.
        3. Making mistakes in addition.  
Ways to help:
        1. Reminding students that their equations should always                have a number from the top and one from the side.
        2. Helping them with basic multiplication by encouraging                them to do REFLEX or other fact games.
        3. Being sure that they line up their numbers correctly when            adding.
        4. Asking if their answer is reasonable by rounding the                original equation.
        5. Practice!
These will certainly assist in success with multiplication of larger numbers.

Please ask your child to explain how they are multiplying. Allowing them to be the teacher will reinforce skills learned in class and help you to understand how they are learning.

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