Custom Excel Sheet Automation Needed

I'm looking for an experienced Excel specialist to create five Excel sheets that automate calculations based on assigned cell values. Each cell will have a manually assigned initial value, and when a numeric value is entered into the cell, it should automatically perform a custom calculation. For example, if cell B4 is assigned a value of 20, entering 10 in that cell should result in a calculation of 200. The sheets should also sum up the results of all relevant cells, such as B5, B6, B7, etc.

Key Requirements:
- Create five Excel sheets with automated calculations
- Allow for manual entry of initial cell values
- Perform custom calculations based on entered numeric values
- Summarize results across specified cells

Ideal Skills and Experience:
- Proficiency in Excel, including advanced formula creation
- Experience with automation and custom calculations in Excel
- Attention to detail and accuracy in setting up formulas
- Ability to provide clear instructions for future adjustments

I look forward to working with someone who can deliver a precise and efficient solution for my needs.