All summed up

Last Task combined all of Part 1. The task wanted a program which let you input 2 numbers and "sum up" everything between them the example.
First: 1
Last: 7
1
3
6
10
15
21
28

The programming involved using the maths from the information given and applying it to this. Grok so far hasn't been too bad but personally having no experience with python, felt like I need better explanation with certain elements of the coding. This half of the week though was fairly challenging but with a bit of help was manageable.  In this half of the week I learnt the following

• for loops
• Looping over a string
• Looping over a range of numbers
• Doing maths with loops