CalcEoki® puzzle collection

AddEoki™

A Puzzle from CalcEoki®

AddEoki is a logic and arithmetic puzzle created by CalcEoki. Every puzzle challenges you to arrange numbers in a 4×4 grid while satisfying a unique combination of mathematical and logical constraints.

Success requires deduction, pattern recognition, arithmetic balancing, and strategic reasoning. Unlike traditional number-placement puzzles, AddEoki combines equal-sum calculations with duplicate-value placement rules — easy to learn, increasingly difficult to master.

A solved grid — every row and column totals 180
10
20
80
70
= 180
80
70
10
20
= 180
30
40
50
60
= 180
60
50
40
30
= 180
180180180180
How to Play

Each puzzle contains

Your objective is to complete the grid so that all puzzle rules are satisfied.

AddEoki starting puzzle grid with clue numbers 10, 80, 80, 10, 50, 20, 40, 50 placed
Starting grid — fill in the remaining cells using each number twice, with equal row and column totals

Numbers — 10, 20, 30, 40, 50, 60, 70, 80

Rules

Five rules govern every grid

1

Use Every Number Twice

  • Each of the eight numbers provided must be placed into the grid exactly two times
  • Each number must appear twice, creating a total of 16 entries
2

No Adjacent Matching Values

  • Identical values cannot touch horizontally or vertically
  • Diagonal touching is permitted unless stated otherwise
3

Equal Row Totals

  • Every row must add up to exactly the same total
4

Equal Column Totals

  • Every column must also add up to exactly the same total
5

Use Logic, Not Guesswork

  • Every official AddEoki puzzle is designed to have a logically deducible solution
  • Difficulty varies by clue count, complexity of number relationships, required deduction depth, and number-placement constraints
Difficulty Ratings

Four levels

Easy

  • More clues provided
  • Suitable for beginners
  • Typically solvable in under 10 minutes

Medium

  • Moderate clue count
  • Requires arithmetic deduction
  • Suitable for regular puzzle players

Hard

  • Fewer clues
  • Multiple deduction stages
  • Requires careful planning

Expert

  • Minimal clues
  • Advanced logical reasoning
  • Designed for experienced solvers
Solving Tips

Where to start

Start by identifying which values have already appeared once
Look for rows or columns that are close to completion
Check whether a number can legally appear without violating adjacency rules
Use row and column totals to eliminate impossible placements
Remember that every number must appear exactly twice
Solution

Completed grid

AddEoki completed solution grid, fully filled in with all sixteen numbers
Completed solution — every row and column totals 180, each number appears exactly twice