### Pair Sums

Five numbers added together in pairs produce: 0, 2, 4, 4, 6, 8, 9, 11, 13, 15 What are the five numbers?

### 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?

### Big Powers

Three people chose this as a favourite problem. It is the sort of problem that needs thinking time - but once the connection is made it gives access to many similar ideas.

# Send Us Your Thoughts

This is the place to share how you got started on the problem, and any conclusions you have reached.

You can also share any questions you've come up with, and any progress you've made answering those questions.

You can upload pictures, documents or spreadsheets - whatever you like, as long as the file is less than 2MB.

You might also want to send a link to a video or picture you've uploaded somewhere else on the web. Please explain a little about what you have done, so we can share it with other students.

It would also be nice to share a little information about everyone who contributes, so please feel welcome to include your name, age, school and country.

Country: