Develop mathematical reasoning with 17 Snail and Crab puzzles and investigations. Children explore different solutions, work systematically and explain how they know an answer works.

This 28-page PDF includes:
• A character-value key and clear puzzle rules
• Addition and subtraction investigations
• Finding combinations and making totals with different cards
• A number crossword
• Routes through a branching plant diagram
• Multiplication and working-backwards challenges
• Digit-sum and shape-counting investigations
• Six pages of answers and teaching prompts
• Guidance for adults, problem-solving strategies and cut-out number cards
• A clickable contents page

Suggested ages: 6–8. Select early puzzles for confident younger learners with adult support. Later tasks include multiplication, larger numbers and working backwards, so choose tasks to match readiness.

Use one investigation at a time with counters, cards or spare paper. Children can draw, make lists and tables, move cards or explain their thinking aloud. Prompts encourage them to find another way, organise solutions and check whether they have found every possibility.

Inspired by One Is a Snail, Ten Is a Crab. The storybook is not included. The booklet retains acknowledgement of puzzle ideas adapted from Mathematical Challenges in the National Numeracy Strategy.

Printable digital PDF. Designed for black-and-white printing.