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How can you express the number 100 using six nines and no other digits?
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∙ 15y ago
9x9+9+9+9/9
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∙ 15y ago
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How do you cast nines?
Casting nines is a method of checking the accuracy of math calculations in addition,subtraction, multiplication and division. It is a "quick check" which flags wronganswers. A great many mistakes in calculation are the result of careless errors andpeople's reluctance to spend time checking their work. Casting nines is quick and easy,once mastered, and many students consider it a game. In many cases, students wholearn and apply this technique will get better grades and have more fun in math. Whenteachers don't have to deal with careless errors, it is possible to move on more quicklyto new math concepts. Warning: This checking method has one limitation. It canoccasionally fail to flag a wrong answer. This happens when a zero is added or left out,when there is a transposition such as 3,528 instead of 3,582, and in some other cases.To cast nines from a number, add the digits:17 1 + 7 = 8 8 is the result of casting the nines.If the sum of the digits is nine, cast (throw away) the nine. It becomes a zero.36 3 + 6 = 9 9 - 9 = 0 0 is the result of casting the nines.If the sum of the digits is more than nine, cast the nines. You will always end up withjust one digit when this is completed: 0, 1, 2, 3, 4, 5, 6, 7, or 8.28 2 + 8 = 10 10 - 9 = 1 1 is the result of casting the ninesInstead of subtracting the nine from a two-digit number as shown above, you may addthe two digits. The result is the same.28 2 + 8 = 10 1 + 0 = 1 1 is the result of casting the ninesHere is an example of casting nines from a large number:5,628 5 + 6 = 11, 1 + 1 (from the 11) = 22 (from the 5 + 6) + 2 (the next digit in 5,628) = 44 (from the 2 + 2 above) + 8 (next digit) = 12, 1 + 2 (from 12) = 33 is the result of casting nines from 5,628To speed up casting nines from large numbers, look for and cross out nines orcombinations which equal nine. Add the remaining digits. For example:5,629,384,2725,629,384,272 Cross out any nines.5,629,384,272 Cross out any combinations which make 9: 5+2+2, 6+3, 7+2Then add any digits still not crossed out: 8 + 4 = 12, 1 + 2 (from the 12) = 33 is the result of casting nines from 5,629,384,272.Once you are able to cast nines from any number, use it to check problems as shown on the next page.Casting NinesAdditionCast nines from both addends and add the one-digit results for the "check number"(circled). Cast nines from the sum. The results must match or the answer is wrong.addend 38 cast nines from 38: 3 + 8 = 11, 1 + 1 = 2addend +76 cast nines from 76: 7 + 6 = 13, 1 + 3 = + 4sum 114 add the two digits to get check number 6Then cast nines from the sum, 114: 1 + 1 = 2 + 4 = 6. This must match the checknumber. If there is no match, thoroughly check the problem to locate and fix the error.MultiplicationCast nines from the multiplicand and the multiplier and multiply the one-digit results forthe "check number" (circled). Cast nines from the product. The results must match.multiplicand 78 cast nines from 78: 7 + 8 = 15, 1 + 5 = 6multiplier x 8 cast nines from 8 (no nines to cast) = x 8product 624 multiply the two digits 48Cast nines from the 48 to get the 1-digit check number: 4 + 8 = 12, 1 + 2= 3Then cast nines from the product, 624: 6 + 2 = 8 + 4 = 12, 1 + 2 (from the 12) = 3SubtractionCast nines from the minuend and the subtrahend. Subtract for the "check number"(circled). Cast nines from the difference. The result must equal the check number.minuend 53 cast nines from 53: 5 + 3 = 8subtrahend - 38 cast nines from 38: 3 + 8 = 11, 1 + 1 = - 2difference 15 subtract the two digits to get check number 6Then cast nines from the difference, 15: 1 + 5 = 6. This must match the check number.In subtraction, the one-digit result on the bottom (subtrahend) may be larger than that on the top (minuend). If this occurs, add a nine to the minuend so subtraction is possible, asshown below. Continue as shown above.minuend 93 cast nines from 93: 3 + 9 =12subtrahend - 44 cast nines from 44: 4 + 4 = - 8 - 8difference 49 subtract the two digits for check number can't do 4DivisionCast nines from the dividend to get the "check number" (circled). Cast nines from thequotient. Cast nines from the divisor. Cast nines from the remainder. Multiply the onedigitresults as is done normally in checking division: quotient times divisor plusremainder. The result must equal the check number.Cast 9's from dividend, 89, for 8 , the check number.quotient 14 r5 remainder quotient 14, 1 + 4 = 5 times divisor 6 = 30 (3 + 0 = 3)divisor 6 ) 89 dividend plus remainder 5 = 8. This matches check number.© 1995 Susan C. Anthony - Reproducible for use with students
Is this a rational number 0.131131113?
If you mean to continue the pattern indefinitely, adding more digits, and one more "1" in every cycle, then it is NOT rational. In the case of a rational number, the EXACT SAME group of digits has to repeat over and over (perhaps after some other, initial, digits), for example:0.45113113113113113... Here, the group of digits "113" repeats over and over, so the number is rational.
What does it mean base 10 system?
This is just decimal, the number system that we usually use. Decimal means that there are 10 digits (0-9) as opposed to other number systems such as binary, which has only two digits.
Which numbers are not divisible by 9?
The divisibility test for the number 9 is: Any number whose digits add up to 9 or a multiple of 9, is divisible by 9. Any other number the sum of whose digits do not add up to 9 or a multiple of 9, are not divisible by 9.For example, the digits of 81 sum up to 9, and therefore, 81 is divisible by 9. The digits of the number 319381482 add up to 39, and therefore, 319381482 is divisible by 9.
When is the product of a decimal number nx10 always a whole number?
When "n" is any other number in the tenths place holder such as .1, .2, .3, ...., .8, .9 and no other digits in any other place holder.
How many strings of four decimal digit have exactly three digit that are nine?
The number of strings of four decimal digits that have exactly three digits which are nine is the number of ways to choose three places to choose the nines multiplied by the number of possibilities for the other digits (because you can put all of the possibilities in an array so that each column has a different way of arranging the nines and that each row has a different set of other digits (because they do not affect each other)). The number of ways to choose the three places to choose the nines is the same as the number of ways of choosing 4-3=1 spot for there not to be a nine. The number of ways of choosing 1 spot where there are 4 spots is 4 (the first, the second, the third, or the fourth). Since there are 9 digits that are not nine, the number of choices for the other digits is 9 (since there is only one digit). Thus, there are 4*9=36 strings of four decimal digits that have exactly three digits which are nine.
How do you cast nines?
Casting nines is a method of checking the accuracy of math calculations in addition,subtraction, multiplication and division. It is a "quick check" which flags wronganswers. A great many mistakes in calculation are the result of careless errors andpeople's reluctance to spend time checking their work. Casting nines is quick and easy,once mastered, and many students consider it a game. In many cases, students wholearn and apply this technique will get better grades and have more fun in math. Whenteachers don't have to deal with careless errors, it is possible to move on more quicklyto new math concepts. Warning: This checking method has one limitation. It canoccasionally fail to flag a wrong answer. This happens when a zero is added or left out,when there is a transposition such as 3,528 instead of 3,582, and in some other cases.To cast nines from a number, add the digits:17 1 + 7 = 8 8 is the result of casting the nines.If the sum of the digits is nine, cast (throw away) the nine. It becomes a zero.36 3 + 6 = 9 9 - 9 = 0 0 is the result of casting the nines.If the sum of the digits is more than nine, cast the nines. You will always end up withjust one digit when this is completed: 0, 1, 2, 3, 4, 5, 6, 7, or 8.28 2 + 8 = 10 10 - 9 = 1 1 is the result of casting the ninesInstead of subtracting the nine from a two-digit number as shown above, you may addthe two digits. The result is the same.28 2 + 8 = 10 1 + 0 = 1 1 is the result of casting the ninesHere is an example of casting nines from a large number:5,628 5 + 6 = 11, 1 + 1 (from the 11) = 22 (from the 5 + 6) + 2 (the next digit in 5,628) = 44 (from the 2 + 2 above) + 8 (next digit) = 12, 1 + 2 (from 12) = 33 is the result of casting nines from 5,628To speed up casting nines from large numbers, look for and cross out nines orcombinations which equal nine. Add the remaining digits. For example:5,629,384,2725,629,384,272 Cross out any nines.5,629,384,272 Cross out any combinations which make 9: 5+2+2, 6+3, 7+2Then add any digits still not crossed out: 8 + 4 = 12, 1 + 2 (from the 12) = 33 is the result of casting nines from 5,629,384,272.Once you are able to cast nines from any number, use it to check problems as shown on the next page.Casting NinesAdditionCast nines from both addends and add the one-digit results for the "check number"(circled). Cast nines from the sum. The results must match or the answer is wrong.addend 38 cast nines from 38: 3 + 8 = 11, 1 + 1 = 2addend +76 cast nines from 76: 7 + 6 = 13, 1 + 3 = + 4sum 114 add the two digits to get check number 6Then cast nines from the sum, 114: 1 + 1 = 2 + 4 = 6. This must match the checknumber. If there is no match, thoroughly check the problem to locate and fix the error.MultiplicationCast nines from the multiplicand and the multiplier and multiply the one-digit results forthe "check number" (circled). Cast nines from the product. The results must match.multiplicand 78 cast nines from 78: 7 + 8 = 15, 1 + 5 = 6multiplier x 8 cast nines from 8 (no nines to cast) = x 8product 624 multiply the two digits 48Cast nines from the 48 to get the 1-digit check number: 4 + 8 = 12, 1 + 2= 3Then cast nines from the product, 624: 6 + 2 = 8 + 4 = 12, 1 + 2 (from the 12) = 3SubtractionCast nines from the minuend and the subtrahend. Subtract for the "check number"(circled). Cast nines from the difference. The result must equal the check number.minuend 53 cast nines from 53: 5 + 3 = 8subtrahend - 38 cast nines from 38: 3 + 8 = 11, 1 + 1 = - 2difference 15 subtract the two digits to get check number 6Then cast nines from the difference, 15: 1 + 5 = 6. This must match the check number.In subtraction, the one-digit result on the bottom (subtrahend) may be larger than that on the top (minuend). If this occurs, add a nine to the minuend so subtraction is possible, asshown below. Continue as shown above.minuend 93 cast nines from 93: 3 + 9 =12subtrahend - 44 cast nines from 44: 4 + 4 = - 8 - 8difference 49 subtract the two digits for check number can't do 4DivisionCast nines from the dividend to get the "check number" (circled). Cast nines from thequotient. Cast nines from the divisor. Cast nines from the remainder. Multiply the onedigitresults as is done normally in checking division: quotient times divisor plusremainder. The result must equal the check number.Cast 9's from dividend, 89, for 8 , the check number.quotient 14 r5 remainder quotient 14, 1 + 4 = 5 times divisor 6 = 30 (3 + 0 = 3)divisor 6 ) 89 dividend plus remainder 5 = 8. This matches check number.© 1995 Susan C. Anthony - Reproducible for use with students
Where is card no on credit card?
The structure of the card number varies by system. For example, American Express card numbers start with 37; Carte Blanche and Diners Club with 38.American Express - Digits three and four are type and currency, digits five through 11 are the account number, digits 12 through 14 are the card number within the account and digit 15 is a check digit.Visa - Digits two through six are the bank number, digits seven through 12 or seven through 15 are the account number and digit 13 or 16 is a check digit.MasterCard - Digits two and three, two through four, two through five or two through six are the bank number (depending on whether digit two is a 1, 2, 3 or other). The digits after the bank number up through digit 15 are the account number, and digit 16 is a check digit.
A number is less than 1000. The sum of its digits is 26. The ones digit is eight. The other two digits are identical. What is the number?
The number is 782. The sum of its digits is 7 + 8 + 2 = 17, not 26. Therefore, no such number exists that meets all the given conditions.
Is the account number be printed in a receipt from an ATM?
The ATM usually prints just the last four digits of the account number. It fills in the other digits with X's
Number system consists of how many digits?
The number system we commonly used, known as the decimal system, has 10 digits (0 to 9). It is possible to use other number systems, with a different number of digits. Any numbering system based on the same principle (the principle of place-value) must use 2 or more digits.
All the other digits are the result of subtracting any number from itself?
Alberto
What is the lowest nine-digit number that can be formed with different digits?
The correct answer is 102,345,678. The number 012,345,678 is considered an eight-digit number; any other rearrangement of the digits, or inserting a 9 in any position, gives a larger number.
Example of mastercard number?
There are 16 digits in a Mastercard number, usually starting with 5.Mostly, they are just an account number. Some of the digits, however, are "check digits." That is, they come from some mathematical formula being applied to some of the other digits. That makes it near impossible to simply make up a string of 16 digits that are a valid credit card number. Of course, the location of the check digits and the formula which generates them are carefully guarded secrets.So, sorry, no example.
What are some What are facts about the number 18?
18 is the only number (other than 0) that is twice the sum of its digits.
How do you epress a number as a fraction of another number?
you use the number you want to express as the fraction as the numerator and the other number is the denominator. an example is, "express 1 as a fraction of 4" you would write it as 1/4
How many digts in credit card?
Technically zero, as there are no numbers in the word "credit card". Otherwise, Visa, Discover, MasterCard, nearly all major companies have 16 digits. American Express on the other hand, have 15 digits.
