The MentalForge cast

Each friend shows you one idea by how they act. Meet them all and see how the ideas fit together.

1. Lefty Left-to-right — add the biggest places first, not last Read the story →
2. Tenna Make-a-ten — round up to a friendly ten, then adjust back Read the story →
3. Halvor Double & halve — double one factor and halve the other Read the story →
4. Soro Soroban beads — picture the beads to add and subtract fast Read the story →
5. Squill Square near a base — square numbers close to 10, 50, or 100 Read the story →
6. Elva The ×11 trick — add each pair of neighbouring digits Read the story →
7. Grandel Subtract from a round number — take from 100 or 1000 by complements Read the story →
8. Crisca Cross-multiply — two 2-digit numbers in one criss-cross Read the story →
9. Nina Cast out nines — a quick check that catches most slips Read the story →
10. Rounda Estimate first — get close, then check the exact answer looks right Read the story →
11. Splitt Break apart — split a hard product into easy distributive pieces Read the story →
12. Abaca the mental-math coach who sets the sprint and reflection Read the story →

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