2 digit x 1 digit multiplication

We have been practicing how to multiply 2 digit x 1 digit problems.  There are many ways and there is no one right way! Each student needs to find their way that works for them.  By the end of third grade, students should be able to solve multiplication problems without a picture.  At home, please keep practicing!!

 

Base Ten Model:

This is a pictural model of how to multiply 2 digit x 1 digit.  Students use a base ten paper and draw out the tens and the ones and find the total by adding the tens and ones together. 

 

Repeated Addition:

Many students feel comfortable adding to find the product.  Students need to decide the better choice, to add 21 groups of 4 or to add 4 groups of 21.  When adding a small number several times, mistakes often happen so students need to be careful.

 

Area Model:

This is taking the base ten model, but simplifying it.  Students need to think of the problem as an array.  The one digit number goes on the left and is multiplied by the two digit number.  The two digit number is broken into the tens and ones.  Then the tens and ones are multiplied by the one digit number.  Then the products are added to find the final product.

 

Partial Products:

This is similar to the area model, but without the boxes.

The 2 digit number is broken into the tens and ones.  These are multiplied by the one digit number.  Then added the two products and find the final answer.

 

https://www.youtube.com/watch?v=XyMGv9LsRGE&feature=player_embedded

To view a video on how to solve these partial products.