Today we've looked at triangular numbers. Did anyone spot a pattern in the way the numbers increase? Can anyone tell me what the 100th triangular number? 5hp for the first answer!
Keep 100 on one side and1 on the other. This is a pair that totals 101. Similarly the next pair is 99 and 2.There are 50 such pairs. Because in a pair there are 2 numbers and total numbers are 100.
The 100th triangular number is 5050
ReplyDeleteGood work Moksh. How did you work that out?
ReplyDeleteKeep 100 on one side and1 on the other. This is a pair that totals 101. Similarly the next pair is 99 and 2.There are 50 such pairs. Because in a pair there are 2 numbers and total numbers are 100.
ReplyDeleteSo the total is101 multiplied by 50 is 5050.
So the100th triangle number is....5050!!!
From number 1->100 has 100 numbers there are 50 pairs of number so we multiply 0.5
ReplyDelete0.5 x(1+100) = 5050
0.5 x(1+100)x 100 = 5050
ReplyDelete