Two-digit by one-digit multiplication October 11, 2013

We have learned how to multiply… Using base ten pieces Ex/ 24 x 3 Using rectangles Ex/ 24 x 3 4 20 + 6 tens & 9 ones 60 + 9 = 69 20 x 3 = 60 4 x 3 = 12 3 60 + 12 72

THINK! Is there a way to use place value without having to draw the rectangle? 24 x 3 24 has 2 tens (20) + 4 ones If I multiply by PLACE VALUE: 20 x 3 = 60 4 x 3 = 12 72 4 20 + 20 x 3 = 60 4 x 3 = 12 3 +

Let’s Make a Connection… When we multiply by PLACE VALUE, which form are we writing the numbers in? 34 x 6 34 = 30 + 4 We are writing the number 34 in expanded form 6 = 6 Can we e-x-p-a-n-d the number 6 anymore? Why?

You’re Turn… Solve the following problem using the All Partials Method: 42 x 7 40 X 7 = 280 + 2 X 7 = 14 294

More Practice! 45 x 8 34 x 9 23 x 7