Page 142 - NUMINO TG_4A

09Door Frame Method Unit

Objective: Practice multiplication of numbers up to 4 digits.

Use the door frame method to multiply 2-digit numbers. Have the students multiply 2-digit numbers
using the Door Frame Method.
12 23 2 The method of drawing is the same as
1 previously learned, but the method of finding
the final product is different. Have the students
Draw 1 and 2 vertical lines. look at this method step by step.
When using the Door Frame Method for the
12 multiplication of 2-digit numbers by 2-digit
2 Draw 2 and 3 horizontal lines. numbers, the result is read diagonally to get
the product.
3

12
2 Mark where the lines cross with a dot.

3

1 2 2 Count the dots by grouping them
3 diagonally ( ). Then read the numbers in
2 6
7 the direction of the arrow.

12 23 = 276

Look at the door frames below. Find the products.

22 32
2 1
1
2

22 21 = 462 32 12 = 384

9. Door Frame Method 75

Example: Find the product of 12 23 by using the vertical form.

12 12 12
23 23 23
3 6 12 3 36 36
2 4 0 12 20 24 0
276

4A Unit 09 125