Developing reasoning and language
Pyramid activity
Lines of enquiry – Year 3
Complete the grid.
What mental calculation strategies did you use?
Repeat the activity with larger numbers
What mental calculation strategies did you use?
Complete the grid.
Did you use any different mental calculation
strategies?
Investigate:
 Does the order of the consecutive numbers in the
bottom row make a difference to the total in the
top row?
 What arrangements of these four numbers (1 2 3
4) make the greatest and smallest totals in the
top row? What is the arrangement for this? Why
does it work?
 What other top-row totals can be made?
 Is it possible to make totals that match all the
numbers between the smallest and biggest totals?
 What patterns can you see in the pyramid?
 What would the effect be on the top number if we
added 1 to each of the four numbers in the
bottom row?
 What would happen if we made the numbers in the
bottom row all odd numbers or all even numbers?
 How many pyramids can you make that have the
top number as 20 using 1 2 3 and 4 on the bottom
row? How do you know when you have them all?
Investigate children’s theories using different sets of
consecutive numbers on the bottom row.