math
posted by Gabby ( 5 grade) .
how would you test to see whether 7 is a factor of 291?

math 
Reiny
I would divide it out and see.
or
write down the number without the last digit
29
subtract twice the digit you skipped
29
2

27
is 27 divisilbe by 7 ?
no ? , then neither was 291
for large numbers checking for divisibility by 7,
repeat the above process until you can tell.
Not very practical, but it works !!! 
math 
Gabby ( 5 grade)
why 2 if the end digit is 1?

math 
Reiny
notice I said, "twice" the number skipped.
2x1 = 2 
math 
Gabby ( 5 grade)
i don't get it i want ms sue to help me!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

math 
Ms. Sue
<g>
Reiny is a REAL math teacher; I'm not.
I'd just divide 291 by 7. 
math 
Gabby ( 5 grade)
WOW I BELIEVED IN YOU:P
Respond to this Question
Similar Questions

Quick math question
Can anyone give me a link to a free online algebra test for 9th graders. I have a test on Monday based on algebra to see if I can move on to Geometery and I need a test to see if I'm ready. Thanks 
Math
Use the Factor Theorem to determine whether x3 is a factor of P(x)=2x^35x^9 . Specifically, evaluate P at the proper value, and then determine whether x3 is a factor. P(_)=__ also pick which one applies x3 is not a factor of P(x) … 
Algebra
Use the Factor Theorem to determine whether x+2 is a factor of P(x)=2x^4+x^33x9. Specifically, evaluate P at the proper value, and then determine whether x+2 is a factor. P(__)= x+2 is or is not a factor of P(x)____ 
IB MATH STUDIES IA
I am finding whether men or women are smarter. I am doing a chisquared test to see if theres a correlation. What other sophisticated processes can i do? 
Statistics!!!
b. The correlation between the number correct on a math test and the time it takes to complete the test is .45. Test whether this correlation is significant for 80 children at the .05 level of significance. Choose either a oneor … 
VERY URGENT SCIENCE
A science teacher was curious to see whether offering money for good grades would increase student performance on a test. The teacher offered half the students in the class $5.00 if they got an A on their next test. The other half … 
Science
A science teacher was curious to see whether offering money for good grades would increase student performance on a test. The teacher offered half the students in the class $5.00 if they got an A on their next test. The other half … 
Science
A science teacher was curious to see whether offering money for good grades would increase student peformance on a test. The teacher offered half of the students in the class $5.00 if they got an A on their next test. The other half … 
statistics
A credit card company estimates that the average credit card balance of Americans is $3,210. A statistics student wants to know whether this is true for citizens of her home town. Which hypothesis test would be most appropriate for … 
Science
A science teacher was curious to see whether offering money for good grades would increase student performance on a test. The teacher offered half of the students in the class $5.00 if they got an A on their next test. The other half …