Open-ended - With worked solutions · SET 11

Use all the numbers 1 to 8, one in each circle, so that the sum along each side is equal. Hint: put 8 and 5 in opposite corners.

Circle the numbers that do not belong to the group.

Write + and − signs in the boxes so that the number sentence is true.

Number riddles. Riddle 1: put it over 4 and it is a half; put it under 1 and it is also a half. Riddle 2: write it after 1 and you are adding 17; write it after 4 and you are adding 44. Find the number for each riddle.

Which of the figures below would appear the same in a mirror? Tick the figure(s).

Complete the number crossword. The numbers in the list must be placed in the grid (one has been done for you).

The dots in the figures represent wet paint marks. The figures are folded along the dotted lines. Write the section number where each dot will appear (A, B and C in both figures).

Study the first two triangles. Then fill in the missing numbers in the other three triangles.

Fill in the boxes with + , −, × or ÷ to make each number sentence true. The first one has been done for you.

Fill in the missing digits: □70□ + 3□98 = 10102.

Find the missing numbers in the sequence below (the top and bottom of the empty boxes).

Fill in the boxes with the numbers 1 to 9 so that each row and each column adds up to 15.

Find the two missing numbers in the sequence: 5, 16, 10, 8, 15, 4, ?, ?

Find the missing numbers in the circles below. Each group of numbers joined by lines adds up to the same total (16).

Fill in the boxes with +, −, × or ÷ to make each number sentence true.

If TREK is 40, 36, 10, 22 and KONA is 22, 30, 28, 2, then what are MARIN, ONZA and XTR?

Which two figures below do not form a pair? Circle them.

The figure consists of a rectangle, a triangle and a circle overlapping at various points. Parts of the drawing are numbered. What is/are (a) the number(s) in the circle, rectangle and triangle only? (b) the number(s) in the rectangle and circle only? (c) the product of the number in the circle only and the number in the circle and rectangle only? (d) the difference between the number in the rectangle only and the number in the triangle only? (e) the sum of all the numbers in the circle?

Fill in the missing digits in the boxes: 7□43□1 − □5512□ = 40□172.

Fill in the boxes with the numbers 1 to 9 so that the addition is correct (the sum is 1962).