Triangular Numbers
What is the 9th triangular number ?
45
What is the equation for the 6th square number ?
6 times 6 is 36
What are triangular numbers are 4th - 8th ?
10 ,15,21,28,36
What is the 4th square number ?
16
What is the 6th triangular number subtracted by the 5th ?
6
What simple method can you use to find a square number ?
Times the number by itself
Why are they called triangular numbers?
Because they can be expressed graphically with triangular arrangements.
What is the 4th through 9th square numbers ?
16 , 25 , 36 , 49 , 64 , 81
`What position is 78 in?
12th
What is the 9th square number plus the 7th minus the 5th?
105