How to Do Double Digit Old Fashioned

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Long multiplication can seem very intimidating, especially if you're multiplying two numbers that are pretty big. If you lot take it step by step, though, y'all'll be able to do long multiplication in no time. Go ready to ace those math quizzes past going to Step 1 below to become started.

1
Write the larger number above the smaller number. Let's say you're going to multiply 756 and 32. Write 756 above 32, making sure that the ones and tens columns of both numbers line up, then that the 6 from 756 is above the ii in 32 and the v in 756 is in a higher place the iii in 32, and and so on. This will make it easier for you to visualize the long multiplication process.^[1]
- You will essentially begin by multiplying the two in 32 by each of the numbers in 756, and then multiplying the 3 in 32 by each of the numbers in 756. Merely let's not become ahead of ourselves.
- The "bigger" number means the one with the virtually digits (numbers).
two

Multiply the number in the ones place of the bottom number by the number in the ones place of the top number. Accept the 2 from 32 and multiply it by the 6 in 756. The production of 6 times 2 is 12. Write the ones digit, 2, under the units, and conduct the 1 over the five. Basically, you lot write downwards whatever number is in the ones digit, and if there is a number in the tens digit, you will have to carry it over the number to the left of the tiptop number you just multiplied. Y'all'll take a 2 directly below the six and the ii.^[two]

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iii

Multiply the number in the ones place of the lesser number by the number in the tens identify of the top number. At present, multiply 2 times v to equal 10. Add the one you carried over above the five to 10 to equal 11, and and then write a 1 next to the 2 in the bottom row. Y'all'll accept to comport the extra 1 in the tens place over the 7.^[3]
4

Multiply the number in the ones identify of the bottom number by the number in the hundreds place of the top number. Now, just multiply 2 by vii to equal xiv. Then add together the i that you carried over to 14 to equal 15. Don't carry the tens over this time, every bit there are no more numbers to multiply on this row. But write the fifteen on the bottom line.^[4]
5

Depict a 0 in the ones column below the commencement product. Now, you'll exist multiplying the number in the tens place of 32, 3, by each digit in 756, so draw a nil beneath the 2 in 1512 earlier y'all begin and then you lot are already starting in the tens place. If you were going to go along going and multiply a number in the hundreds place by the acme number, then you'd need to draw 2 zeroes, and so on.^[five]
6

Multiply the number in the tens place of the bottom number past the number in ones place of the summit number. At present, multiply 3 by half-dozen to equal 18. Again, put the eight on the line, and carry the ane over above the 5.
vii

Multiply the number in the tens place of the bottom number past the number in tens identify of the meridian number. Multiply iii times 5. This makes 15, simply y'all must add on the carried 1, so information technology equals xvi. Write the half dozen on the line, and carry the 1 over higher up the 7.
8

Multiply the number in the tens place of the bottom number by the number in hundreds place of the height number. Multiply 3 times seven to equal 21. Add the 1 you carried to equal 22. You don't need to carry the two in 22, as there are no more than numbers to multiply on this line, so you can just write it down side by side to the vi.
ix

Add the ones digits of both products. At present, you'll have to but add together up 1512 and 22680. Offset, add ii plus 0 to equal 2. Write the result in the ones column.
x

Add the tens digits of both products. At present, add together upwardly 1 and viii to equal 9. Write 9 to the left of the 2.
11

Add the hundreds digits of both products. The sum of five and vi is eleven. Write down the 1 in the ones place and carry the i in the tens place over one at the very left of the first product.
12

Add together the thousands digits of both numbers. Add up 1 plus 2 to equal 3 and then add on the 1 you carried over to equal four. Write it downwards.
13

Add the 10 thousands digits of both numbers. The first number has nothing in the ten thousands place, and the second has ii there. So, add together 0 plus 2 to equal 2 and write it down. This gives you 24,192, your final reply.
14

Check your respond with a calculator. If you want to double check your work, type in the problem into a calculator to run across if you've done it correctly. Y'all should get 756 times 32 equals 24,192. You're all done!

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1

Write down the problem. Let'due south say you're multiplying 325 times 12. Write it downwardly. One number should exist right next to the other, non below it.^[half-dozen]
2

Split up the smaller number into tens and ones. Keep 325 and separate up 12 into x and 2. The 1 is in the tens digit, and then you should add together a 0 afterward to go along its place, and since the 2 is in the ones place, y'all tin can just write down 2.^[7]
3

Multiply the larger number by the number in the tens digit. Now, multiply 325 times 10. All yous have to do is add a zero to the end to equal 3250.^[8]
iv

Multiply the larger number by the number in the ones digit. Now, just multiply 325 by 2. Y'all can eyeball it and run across that the answer is 650, since 300 times two is 600 and 25 times ii is 50. Add together upwardly 600 and 50 to equal 650.
five

Add upwards the ii products. Now, just add together upwardly 3250 and 650. You can practise this using the good old fashioned addition method. Just write 3250 over 650 and practice all the work. You lot'll get three,900. Really, this is like to doing the standard long multiplication, but splitting upward a number into ones and tens allows you to do a bit more of the math in your caput and to avert multiplying and conveying too much. Either method will yield the same results, and information technology all depends on which 1 works more than quickly for you.

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Question

What can I practise if I am dislocated past all of the zeroes on the finish of the numbers?

John paul56

Community Reply

Set bated start the zeros (but remember how many there are). Multiply the non-goose egg numbers, then add all the zeros that you set aside beforehand.
Question

How practise I do the checking in a multiplication process?

Employ a calculator to check your answer, or if non possible, use long partitioning to divide your answer by one of the numbers and see if you lot become the other number.
Question

How can I solve money bug without using a calculator?

Coin problems aren't also complicated, just exercise the problem like a normal ane and put the decimal in front of the concluding two numbers.
Question

How do I know what number to carry over?

You will know to carry the number over if it is a two digit number. The first of the two digits is the one that you carry over.
Question

Wouldn't information technology exist easier to use punnet squares? It'due south more curtailed, and doesn't require y'all to seemingly add zeros arbitrarily.

Punnet squares may be useful to a geneticist, simply they're non applicable in about multiplication questions.
Question

Can I use repeated addition?

Aye, although it takes longer. In one case you become comfortable with the multiplication process, it will be a much more efficient apply of your time.
Question

How do I multiply a long decimal number by a shorter 1?

At kickoff multiply the two numbers together as if there were no decimals points in either number. And then add up the number of decimal places to the right of the decimal points in both multipliers, and identify the decimal betoken in the concluding product so that the number of decimal places in the product is the same as the full decimal places in the ii multipliers. For case, 9.8649 multiplied by vii.3 equals 72.01377, with four decimal places in i multiplier, one decimal place in the other, and five decimal places in the product.
Question

How do I exercise long sectionalization for 561 / 3?

You lot would apply short sectionalisation in this case (considering dividing by 3 is so easy). three goes into 5 once with a remainder of 2. 3 goes into 26 eight times with a balance of 2. 3 goes into 21 seven times. The quotient is 187.
Question

The process you show in the kickoff example is how I have always done multiplication. Why are students today taught such a long and convoluted procedure to reach the same reply?

The second method is actually the get-go method dressed a picayune differently. It's offered in the promise that some students might find in it an explanation of the first method.
Question

How practice I multiply large numbers?

The process is the same as with shorter numbers. You just take more partial products to add together at the terminate.

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Practice on short, easy numbers first.
Make sure you go your numbers in the right columns!
Don't forget to acquit your tens along, or else it'll all mess upwardly.
Ever put a 0 at the end on the tens. on the hundreds put TWO 0's and then on. As well, cheque your work thoroughly and utilize a figurer afterwards - simply no adulterous.
For numbers of more than ii digits, follow these steps: first multiply the top number by the units, and then add a zero and multiply by the tens, then add ii zeros and multiply past the hundreds, and then add three zeros and multiply by the thousands, and so on. Add up all the numbers at the end.
Use division to check your answer.

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Commodity Summary X

To do long multiplication apace, start by splitting upward the tens and ones place in the smaller number. For case, if the number was 12, you would end up with 10 and 2. Next, multiply the bigger number by both the tens number and the ones number. Finally, add the 2 products together to go your final answer. To learn how to write out a long multiplication problem by mitt, keep reading!

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