- Large amount of multilink cubes
- Whiteboards and pens
- Give the children 9 multilink cubes each, or per pair if they are in short supply. Ask the children to make any arrangement of cubes they like, providing they use all the 9 cubes available.
- When everyone has completed their configurations, ask the children to hold them up so that they can all see each other’s. Ask if anyone has made a square using the 9 cubes (a 3 x 3 formation). In the unlikely event that no one has created this configuration, have one handy. Show it to the children and ask what the square root of 9 is (3) or, in other words, which number was squared to get 9 cubes.
Teaching point: Children are often confused by terms like ‘squared’ and ‘square root’ and this visual method is designed to show them that the cubes quite literally make a square.
- Now ask the children if every number is a square number (no) and why that it the case. They should be able to tell you that square numbers are only those which form a square when created with cubes. So, 4, 9 and 16 could be arranged in squares, but 5, 6, 7 and 8 cannot.
- Give each child (or pair) a good amount of multilink and ask them to make some square numbers. They should note the square root (the number of cubes used on one of the square’s sides) and the square number itself.
- A video at https://www.youtube.com/watch?v=K-TN6WUjyhU shows all the square numbers up to 152. Pause the clip after each one to show the configuration. Make links to the children knowing their times tables in order to avoid having to use lots and lots of cubes!
- Move on to cubed numbers when appropriate. Give each pair of children 27 cubes and ask them to form a cube which is 3 cubes wide, high and long. Ask the children to write the calculation for the number of cubes they have just used (3 x 3 x 3). How could we work out other cubed numbers without using anymore cubes?
- Let the children work together to write the calculations for cubed numbers – noting which children can go the highest.
Make cardboard cube nets which have lines to divide them and give the appearance of being made from cubes. Hang them up in order, from 23 up to 103 as a visual reference for the children.
Practise counting in squared numbers to reinforce the sequences.
Use multilink cubes to make further visual references of squared numbers which can remain on permanent display.
Organise a triangular number investigation using isometric paper – ask the children to conclude any rules or patterns in the triangular number sequence.
Curriculum Areas covered:
(Y5)Pupils should be taught to:
- recognise and use square numbers and cube numbers, and the notation for squared ( 2 ) and cubed (3 )