Number puzzles - Section 1
Practice and master this topic with our carefully crafted questions.
Working in rows, in each row the central number is equal to the difference between the sum of the even numbers in the row and the sum of the odd numbers in the row.
Starting with the numbers in the top row, left to right, multiply each one by 2 and write the results in the lower row, from right to left.
Starting at the top, double each number and add 7 to give the next number down.
In each diagram, the number at the top equals the average of the four smaller numbers.
Starting on the top left, and moving clockwise around the diagram, add the first two values together to give the next value along. Repeat this sequence.
The sum of numbers in each row and column equals to 15.
Divide the diagram in half, horizontally and vertically, to give 4 squares, each 3x3. In each square, add up the 4 outer numbers, and put the result in the centre block.
Starting with the circle on the top left, and moving to the right, top row then bottom row, the sum of the numbers in each circle follows the sequence 12, 15, 18, 21 etc.
Taking any side of the triangle, the sum of the two corner digits is written in one of the circles on that side, and the difference is written in the other circle.
Starting with the top left number, and working down one row at a time, alternating between left and right, double the number each time.Repeat this sequence, starting with the top right number.