### Summing Consecutive Numbers

Many numbers can be expressed as the sum of two or more consecutive integers. For example, 15=7+8 and 10=1+2+3+4. Can you say which numbers can be expressed in this way?

### Always the Same

Arrange the numbers 1 to 16 into a 4 by 4 array. Choose a number. Cross out the numbers on the same row and column. Repeat this process. Add up you four numbers. Why do they always add up to 34?

### Fibs

The well known Fibonacci sequence is 1 ,1, 2, 3, 5, 8, 13, 21.... How many Fibonacci sequences can you find containing the number 196 as one of the terms?

# Sum Equals Product

##### Stage: 3 Challenge Level:

The sum of the numbers 4 and $1 \frac{1}{3}$ is the same as the product of 4 and $1 \frac{1}{3}$;
that is to say $4 +\frac{4}{3} = 4 \times \frac{4}{3}$. What other numbers have the sum equal to the product and can this be so for any whole numbers?

What relationship must exist between the numbers?