How to calculate 78 multiplied by 21 using long multiplication

How to calculate 78 multiplied by 21

How to calculate 78 multiplied by 21 using long multiplication. Here is step-by-step how to calculate 78 times 21 using long multiplication:

Step 1: Setup
Set up your multiplication problem like this:

	7	8
x	2	1

Step 2: Multiply
8 x 1 = 8. Put 8 below the line and 0 as a reminder on top:

	0
	7	8
x	2	1
		8

Step 3: Multiply
1 x 7 = 7. Take 7 and add 0 from the previous step to get 7. Enter 7 at the bottom:

	7	8
x	2	1
	7	8

Step 4: Add 0
Enter a 0 at the bottom right as a place holder, because you now move over one digit:

	7	8
x	2	1
	7	8
+		0

Step 5: Multiply
2 x 8 = 16. Put 6 below the line and 1 as a reminder on top:

	1
	7	8
x	2	1
	7	8
+	6	0

Step 6: Multiply
2 x 7 = 14. Take 14 and add 1 from the previous step to get 15. Enter 15 at the bottom:

			7	8
x			2	1
			7	8
+	1	5	6	0

Step 7: Add to get answer
Add up the bottom two numbers (78 + 1560 = 1638) to get the answer:

			7	8
x			2	1
			7	8
+	1	5	6	0
=	1	6	3	8

The bottom line is the answer. Therefore, 78 times 21 equals:

1638

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How to calculate 79 multiplied by 21
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