打 · Addition
Scroll of the Strike
Adding fast is not about memorising every sum. It is about seeing how numbers fit together and taking the shortest path to the answer.
Ten Partners
Learn the pairs that make ten: 1+9, 2+8, 3+7, 4+6, 5+5. Fill up to ten first, then add what is left.
7 + 5
- → 7 needs 3 to reach 10
- → 5 − 3 leaves 2
- → 10 + 2 = 12
Answer: 12
Practice: Try 8 + 6, 9 + 7 and 6 + 5 by filling to ten first.
Twin Strike
Know your doubles by heart. When two numbers are neighbours, double the smaller one and add the difference.
6 + 7
- → Double 6 = 12
- → 7 is one more than 6
- → 12 + 1 = 13
Answer: 13
Practice: Try 8 + 9, 15 + 16 and 25 + 24.
Left-Hand Flow
At school we add from right to left on paper. In your head, start with the biggest place value and move right.
437 + 51
- → Hundreds: 400
- → Tens: 30 + 50 = 80 → 480
- → Ones: 7 + 1 = 8 → 488
Answer: 488
Practice: Try 35 + 42, 264 + 123 and 518 + 71.
Borrowed Hundred
When a number sits close to a round number, use the round number and give back the difference afterwards.
56 + 99
- → 99 is 100 − 1
- → 56 + 100 = 156
- → Give back 1: 156 − 1 = 155
Answer: 155
Practice: Try 47 + 98, 135 + 199 and 64 + 29.
Into the dojo
Practise with the Strike + technique in Kung Fu Math or Junior, white belt and up.