1. How to use:

①. Direct addition Direct reduction

1. Direct addition essentials: When adding, look at the outer beads, if enough, add directly.

Exercise: 2+2 | 3+1 | 2+1 | 5+3 | 3+5

4+5 | 1+5 | 2+5 | 1+7 | 2+6

2. Essentials of direct reduction: Look at the inner pearl for reduction, if enough, the reduction will be direct.

Exercise: 4-2 | 4-3 | 6-1 | 8-2 | 7-5

8-5 | 9-5 | 9-4 | 8-7 | 9-8

②. Five additions and five deductions

1. Tips for adding five points: If the addition is not enough, add five points and subtract five points to make up.

Practice: 4+4 | 2+3 | 3+3 | 4+3

2. The key to defeating the five-minus problem: Subtracting it down is not enough, subtracting it by five and adding it up.

Exercise: 8-4 | 7-3 | 6-2 | 5-2

③. Carry plus carry and subtract minus

1. Carry plus essentials: This file is full Ten, subtract and supplement by one.

Exercise: 2+8 | 3+7 | 4+6 | 5+5

4+7 | 4+8 | 3+9 | 2+9

2. Abdication Tips for subtracting: If the current level is not enough to reduce, drop one to make up.

Practice: 11-7 | 12-8 | 11-5 | 10-5

15-8 | 16-9 | 13-4 | 11-9

④. Break five Carry and carry out, then subtract five when the number is full

1. The key to adding when breaking the five-digit number: If the current file reaches ten, add one forward, subtract five, and add up.

Practice: 5+6 | 7+7 | 8+6 | 5+9 |

6+7 | 5+8 | 6+6 | 6+8

2. Tips for deducting five points if you abdicate: The current level is not enough to reduce, so if you step down and add five points, you can make up for it.

Exercises: 12-6 13-8 13-7 11-6

12-7 14-8 14-7 13-6