A. Single-color Zongzi reduction method

Step 1: Return the corner blocks

Key points: First, put four big corners around the same central block (that is, the same surface). At this time, four small corner blocks are on its bottom surface, and then R2, U

can be the first

. Two center blocks on the f plane are adjusted at the same time: (r

u'

r) (u

r

u

r) (u'

r'

u')

② Adjustment direction of a single center block: (r

u' r. T-shaped block direction adjustment

③ The direction of the upper and lower (i.e. front and rear) trapezoidal blocks on the U plane is adjusted simultaneously: (m

u

m

u

U2) (m'

u

m'

u

m') < Bottom cross

key points: ① The method is the same as that of the third-order Rubik's cube, regardless of the direction of trapezoidal blocks (also known as edge blocks)

② Pay attention to the correct direction of large corner blocks

Step 2: Restore the second layer (F2L)

Key points: ① Observe the position of the center block of the second layer, regardless of the direction. Regardless of the direction

Step 3: Return the top corner block

① Counter-clockwise triangle change: x'

(r

u' r)

D2

(r'

u

r

)

D2

R2

.

③ diagonal change (changing the left rear edge block at the same time): f (r

u'

r'

u') (r

u

r'

f') (r

u

r'

u'

(R2

u'

r'

u'

r

u

r'

f')

Step 4: Turn the top corner

Key point: Place the top corner to be turned in the lower right position of the U-plane. This step can also be put after the fifth or sixth step, and the formula of

① turning the vertex angle 9 degrees clockwise is (r'

d'

r

d) × 2

u'

(r'

d'

r

d )× 4

. ×4

U'

③ Make the two large corners of the U-plane rotate 9 degrees counterclockwise at the same time (actually, the four corners reverse 9 degrees at the same time):

(r'

d'

r

d )× 2

u

(r'

d' ×2

U2

④ Make the two large corners of the U-plane rotate 9 degrees clockwise at the same time (actually, the four corners rotate 9 degrees clockwise at the same time):

(r'

d'

r

d )× 2

u'

(r'

d' Regardless of the direction)

①PLL's counter-clockwise triangular conversion formula: (r

u'

r) (u

r

u

r) (u'

r'

u' R2)

② PLL's clockwise triangular conversion formula: (R2 <

③PLL

formula m2

u

m2

U2) (

m2

u

m2

)

Step 6: Rectify the direction of trapezoidal block

Key points: (1) All formulas are used, with special attention to X. Place the T-shaped block to be straightened at the right and front positions of the center block of the U-plane

①: (r

u > r'

u')

r

(r'

u

r

u')

r'

.

y'

②: r

(u

r' u')

r'

(

r

u

r

u'

r')

y

. Turn f clockwise:

(U'

D

L'

R

F'

B

)

u'

(f

b'

l

r'

u.

u

(f

b'

l

r'

u

d'

) f'

③ The plane U and the plane F are turned 18 degrees at the same time:

(u'

d

L.