SaiBook.us Multiplication

Lesson Example Discussion Quiz: Class Homework

Example

Title: Multiplications

Grade: 4-a Lesson: S1-L4

Explanation: The best way to understand multiplications is by looking at some examples. Take turns and read each example for easy understanding.

Examples:

Step: 1a

Find the product of 42 x 29

Place the multiplicand 42 on top, and the multiplier is 29.
Multiply the ones digit of the multiplier 9 with the multiplicand 42.
This will give 42 × 9 = 378. This is the first partial product that will be placed in one line."

$1a$

Explanation: In this step, multiply 42 by 9. Multiply 2 by 9 to get 18. Place 8 in the one’s place, and carry 1 to the tens column. Multiply 4 by 9 to get 36. Add 36 to the carry-over of 1 to get 37. We get the answer is 378. This is the first partial product placed in one line.

Step: 1b

Multiplying with the tens column.This will give 42 × 2=84. Write a 0 in the one’s column as shown below.
Multiply the one’s digit on the top number with the ten’s digit of the bottom number, i.e., 2 × 2 = 4
Multiply the tens digit on the top number and the tens digit of the bottom number, i.e., 4 × 2 = 8. The value of a second partial product is 840.

$1b$

Explanation: In this step, multiply the bottom tens digit, which is 2, by the number on the top which is 2. So, 2 x 2 = 4. Write down the number 4 next to the 0. For 4 x 2 = 8, write down the number 8 next to the 4 that you already wrote down. This way, you will get the final answer of 840. This is the second partial product placed in another line.

Step: 1c

Add both partial products to get the final product
This will be 378 + 840 =1218.

$1c$

Explanation: Add both of your results to get a final answer. Now need to add 378 + 840 to get 1218.