March puzzle answers
Six winners in Math Mania contest
Just as last month, there were six winners in the March
Math Mania contest. And, as we did last month, we picked three
winners of $10 Border book certificates in a random drawing.
The March contest involved manipulating three-four- and five-digit
numbers.
The six entrants who got all the answers correct were:
Anthony Cataldo, Ashleigh Johnson, Faith
Salamon, John Simon, John McCann and Ryan
Wahidi, who is getting to be a regular winner.
The three chosen for the $10 certificates were:
Faith Salamon, John Simon and Ryan Wahidi
If you'd like to enter the April Math Mania contest, click
here.
March Math Mania Challenge:
Three, Four, and Five-Digit Fun
| Find the largest
three-digit number … HINT:
Work backwards from 1,000 and try to find the first number
which satisfies the criteria. |
| 1. whose digits are
all prime. |
Answer:
777 |
| 2. that is divisible
by both 3 and 10. |
Answer: 990 |
| 3. whose digits have
a sum of 16. |
Answer: 970 |
| Find the largest
four-digit number… HINT:
Work backwards from 10,000. |
| 4. that is divisible
by 2, 4, and 5. |
Answer: 9,980 |
| 5. that is a palindrome.
|
Answer: 9,999 |
| 6. that is a multiple
of 7. |
Answer:
9,996 |
| Find the largest
five-digit number… HINT: Work backwards from 100,000. |
| 7. whose first digit
is the sum of the last four. |
Answer:
99,000 |
| 8. that is a multiple
of 75. |
Answer:
99,975 |
| 9. whose five different
digits have a sum of 17. |
Answer:
95, 210 |
