Natural numbers - 8th grade (13y) - math problems

Number of problems found: 180

  • Unknown numbers
    eq222_3 The sum of two consecutive natural numbers and their triple is 92. Find these numbers.
  • All pairs
    cisla Determine all pairs (m, n) of natural numbers for which is true: m s (n) = n s (m) = 70, where s (a) denotes the digit sum of the natural number a.
  • Three-digit
    seven How many do three-digit natural numbers not have the number 7?
  • Big numbers
    numbers_1 How many natural numbers less than 10 to the sixth can be written in numbers: a) 9.8.7 b) 9.8.0
  • AM of three numbers
    arithmet_seq The number 2010 can be written as the sum of 3 consecutive natural numbers. Determine the arithmetic mean of these numbers.
  • Twenty-five
    prime How many are three-digit natural numbers divisible by 25?
  • Sum of seven
    numbers_5 The sum of seven consecutive odd natural numbers is 119. Determine the smallest of them.
  • Three-digit integers
    numbers2_49 How many three-digit natural numbers exist that do not contain zero and are divisible by five?
  • Count of roots
    eggs How many solutions has equation x. y = 7757 with two unknowns on the set of natural numbers?
  • Rectangles
    rectangles How many rectangles with area 8713 cm2 whose sides are natural numbers are?
  • Two numbers 7
    numbers_49 The sum of two consecutive even numbers is 30. Find the numbers.
  • A three-digit numbers
    clocks_1 Determine the total number of positive three-digit numbers that contain a digit 6.
  • Telephone numbers
    phones How many 7-digit telephone numbers can we put together so that each number consists of different digits?
  • Odd numbers
    friends4_2 The sum of four consecutive odd numbers is 1048. Find those numbers ...
  • Unknown number 7
    percents2_9 16% of the unknown number is by 21 less than unknown number itself. Determine the natural unknown number.
  • Three-digit numbers
    numbers_49 Use the numbers 4,5,8,9 to write all three-digit numbers without repetition. How many such numbers are there?
  • Algebrogram
    numbers_26 Solve algebrogram for sum of three numbers: BEK KEMR SOMR ________ HERCI
  • Progression
    sequence_geo_10 -12, 60, -300,1500 need next 2 numbers of pattern
  • Even / odd numbers
    parne_neparne a / Using variable n write two consecutive odd numbers. b / the sum of three consecutive odd numbers is 333. What are this numbers?
  • Real estate
    house Residential house has three entrances numbered by odd numbers arithmetic progression. The sum of the two numbers on the corner entrances is 50. Calculate the highest of this three numbers.

Do you have an interesting mathematical word problem that you can't solve it? Submit a math problem, and we can try to solve it.



We will send a solution to your e-mail address. Solved examples are also published here. Please enter the e-mail correctly and check whether you don't have a full mailbox.

Please do not submit problems from current active competitions such as Mathematical Olympiad, correspondence seminars etc...
Natural numbers - math problems. Examples for 8th grade.