Mathematical Investigation

Number Stairs

Look at the shape that looks like stairs on the big 10x10 grid. It has 3 steps. If you add up all the numbers inside it, you get 194.

A 3-step stair hanging from 45 has a stair total of 194.

Try this with other 3-step stairs by clicking numbers on the grid. Can you see a pattern between the total number and where the stairs are hanging?

Now, try looking at stairs with different numbers of steps on different grids. Can you find a pattern with those totals?

rows and columns

2-step 3-step 4-step 5-step

Adapted from a resource created by D.Keith at and shared with a creative commons licence.


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