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The best way is to use the method that was used for centuries - until the modern calculators became ubiquitous - estimate the answer.
Consider, for example,2045078 * 9087054 = 18583734220212
Estimate: 2 million * 9 million is 18 million.
So (2 million plus a bit) * (9 million plus a bit) = 18 million plus a bigger bit.
Yes, that does look like it!
A more accurate method is to do carry out a "digital root" check.
A digital root of a multi-digit number is calculated by adding together all the digits. If the answer is greater than 8 then keep repeating with the digits of the answer, until it is not. Equivalently, add together the digits but every time you come to 9 put the sum back to 0.
Then the digital root of the product must equal the product of the digital roots.
Back to the above example:
DR(2045078) = DR(26) = 8 [26 = 9*2 + 8]
DR(9087054) = DR(33) = 6 [33 = 9*3 + 6]
DR(18583734220212) = DR(48) = DR(12) = 3 [48 = 9*5 + 3]
The DR of the left hand side (LHS) of the DR equations is DR(8*6) = DR(48) = 3
and that of the right hand side (RHS) is also 3.
So the multiplication is probably correct. The method is not fool-proof. Errors due to swapping digits are untraceable. Also, replacing 0 by 9 or 9 by 0 cannot be checked.
The latter kind of mistake can be identified if you repeat with DR7, the digital roots in which you discard 7s. So
DR7(2045078) = DR(26) = 5 [26 = 7*3 + 5]
DR7(9087054) = DR(33) = 5 [33 = 7*8 + 5]
DR7(18583734220212) = DR(48) = 6 [48 = 7*7 + 6]
Now DR7(LHS) = DR7(5*5) = DR7(25) = 6 = DR7(RHS).
What else can I help you with?
A number with more then one digit is called what?
It can be called:* Multidigit * Greater or equal to ten
Which operation should be used to check the answer to a division problem?
Multiplication
Why you can use multiplication to check a division problem?
multiplication is the Inverse operationof division so it could be used to check my work
How do you check multiplucation with division?
To check multiplication with division, you can divide the product of the multiplication by one of the original factors. If the result equals the other factor, then your multiplication is correct. For example, if you multiply 6 by 4 to get 24, you can check by dividing 24 by 6, which gives you 4, confirming the original multiplication. This method ensures that both operations are consistent with each other.
How is multiplying by multidigit numbers similar to multiplying by two digit numbers M?
Multiplying by multidigit numbers is similar to multiplying by two-digit numbers in that both processes involve breaking down the numbers into smaller, more manageable parts. In both cases, you apply the distributive property—multiplying each digit of one number by each digit of the other. This often involves carrying over values, similar to traditional multiplication methods. Ultimately, both processes aim to arrive at the same final product through systematic addition of the partial products.
A number with more then one digit is called what?
It can be called:* Multidigit * Greater or equal to ten
Which operation should be used to check the answer to a division problem?
Multiplication
How do you check your divsion?
With multiplication.....
Why can multiplication be used for solving division?
so when you find your answer you can check it by using multiplication.
Why you can use multiplication to check a division problem?
multiplication is the Inverse operationof division so it could be used to check my work
How do you check multiplucation with division?
To check multiplication with division, you can divide the product of the multiplication by one of the original factors. If the result equals the other factor, then your multiplication is correct. For example, if you multiply 6 by 4 to get 24, you can check by dividing 24 by 6, which gives you 4, confirming the original multiplication. This method ensures that both operations are consistent with each other.
How do you check for reasonableness within a multiplication problem?
56x34
How is multiplying by multidigit numbers similar to multiplying by two digit numbers M?
Multiplying by multidigit numbers is similar to multiplying by two-digit numbers in that both processes involve breaking down the numbers into smaller, more manageable parts. In both cases, you apply the distributive property—multiplying each digit of one number by each digit of the other. This often involves carrying over values, similar to traditional multiplication methods. Ultimately, both processes aim to arrive at the same final product through systematic addition of the partial products.
Matrix multiplication using mpi?
Check related links
When doing a math problem dividing how can you check your problem?
You can multiply the answer to see if it's right. same with multiplication, addition, and subtraction. Multiplication, you divide, to check addition, you subtract, and subtract, you add.
How can you check the product of a multiplication problem?
YoU CaN DiViDe. its called inverse opperation.
Why can you use fraction multiplication to check the answer to a fraction division problem?
You can use fraction multiplication to check a fraction division problem because dividing by a fraction is equivalent to multiplying by its reciprocal. For example, if you need to solve ( \frac{a}{b} \div \frac{c}{d} ), you can multiply ( \frac{a}{b} ) by ( \frac{d}{c} ). If your division is correct, the result of this multiplication will match your original answer. Thus, verifying the answer through multiplication provides a reliable check.
