Games
Problems
Go Pro!

The Middle Palindrome

Pro Problems > Math > Number and Quantity > Number Theory > Digits
 

The Middle Palindrome

If all the palindromes between 100 and 1000 were listed in order from smallest to largest, what is the average of the two numbers in the middle of the list?

NOTE: A palidrome is a number which reads the same forward and backward. For example, if you reverse the digits of 97279, you still have 97279.

Presentation mode
Problem by Mr. Twitchell

Solution

In order to make it feasible for teachers to use these problems in their classwork, no solutions are publicly visible, so students cannot simply look up the answers. If you would like to view the solutions to these problems, you must have a Virtual Classroom subscription.
Assign this problem
Click here to assign this problem to your students.

Similar Problems

Three Digit Number

I'm thinking of a three-digit number. The sum of its digits is between 15 and 20 exclusive. The product of my first and last digits is 18. I don't have any repeated digits, and my digits are not in either ascending order or descending order. I am a multiple of three, but not of six. What number am I?
 

Coffee Math

Johann was writing out a math problem when he spilled some coffee on his paper. The result was that some digits were covered up, as shown below.

  ♦7♦
+ ♦♦9
-----
  50♦

If all but one of the hidden areas have the same digit, find all possible values for the sum of the hidden digits

My Three Digits

I'm thinking of a three-digit number. The sum of my number's first and last digits is a perfect square. The sum of my number's first and second digits is also a perfect square. If my third digit is subtracted from my second digit, the result is 5. If my number is not a multiple of three, and it has no repeated digits, what is my number?

Five Digit Number

The sum of the digits of a three digit number is eighteen. The first digit is three more than the last digit. There is a repeated digit in the number. What are all possible values of the number?

Fiona's Telephone Number

When Shrek asks Fiona for her telephone number, Fiona is a bit coy about it, and tells Shrek the following information:

  • My telephone number has 10 digits.
  • There are no repeated digits in my telephone number.
  • The first three digits are in ascending order.
  • The second three digits are in descending order.
  • Both the last four digits and the last two digits are multiples of sixty.
  • My last four digits are not a multiple of 43.
  • My first three digits are the square of an integer less than twenty.
  • The sum of the second three digits is 14.

What number should Shrek dial?

Three Digit Difference

Two positive integers, A and B, both have 3 digits. A is bigger than B. A – B is between 300 and 400. What is the value of A - B?

 

All My Digits

All my digits are non-zero perfect squares. If you treat my first two digits as a two-digit number, and treat my last two digits as a two-digit number, the sum of these two numbers is also a perfect square. If I am a three digit number, what numbers could I be?

Happy New Year

Happy New Year! I am a four-digit year, and my last two digits are a perfect square. The sum of my first and third digits is a perfect square. My second digit is a perfect square. All my digits add to a perfect square.

If you subtract my first, second, and third digit from my last digit, you get a perfect square.

If you subtract my third digit from my first digit, you get a perfect square.

Oh, by the way, I'm a perfect square.

What year am I?

Three Digits, sum and product

I'm a three digit number. My first two digits multiply to 12, and my last two digits add to 14. What number am I?

I Have Three Digits

I am a three digit number, and the following things are true about me:

  1. The product of two of my digits is 8.
  2. The sum of my digits is 13.
  3. My first digit is four times my second digit.

What number am I?

Reverse Me, Grapes on the Vine, Digits in a Multiplication Problem, Back to Back, Find the Number, Three Digit Number, Palindrome Addition, Four Digit Number, Set of Five Digit Numbers, Sum of Digits, Three Digits with Difference, Rhonda's Zip Code, Fill in the blanks, Two Digit Pattern Matching

Blogs on This Site

Reviews and book lists - books we love!
The site administrator fields questions from visitors.
Like us on Facebook to get updates about new resources
Home
Pro Membership
About
Privacy