Missing number in a grid — Logical reasoning for kids

How to think it through

Full rows first — “the complete rows (or columns) show the rule; the row with the ? uses the same rule”

1. Look at a full row: do the first two numbers add, take away or multiply to make the third? Is the row total the same in every row?
2. Check the same rule on the other full row. If rows do not work, try the columns.
3. Use the rule on the row with the ?.

Use it for: Figure and grid puzzles in Olympiads and aptitude tests, and practice with mental adding and times tables.

Worked example: Find the missing number. The same rule works in every row or in every column.
3 | 5 | 8
6 | 2 | 8
7 | ? | 16 = 9

✏️ Practice

Work it out in your head or on paper, then tap your answer — or type it and press Check. Stuck? Press “Show me how”.

🏁 Lesson 6 test

20 questions. Check each answer, then go to the next one. Get 16 or more right to pass.

🏅 Sign in with Google to earn the 🧮 Grid Guru badge when you pass — and a certificate when you finish all 10 lessons of Part 1 · Patterns. You can still take the test without signing in.

🖨️ Missing Number Grid Worksheet

• Worksheet set 1 (PDF)
• Worksheet set 2 (PDF)
• Worksheet set 3 (PDF)