The Middle Layer

1. The Middle Layer Lesson 4 Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

2. GOAL:The Middle Layer The goal of this stage is to get the Middle Layer (the horizontal middle row) with the WHITE Face as the DOWN Face. Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

3. ¼ Turns R Ri L Li D Di U Ui B Bi F Fi • Inverted means opposite • By inverting a move, • the move can be undone Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

4. Position a WHITE corner on the BOTTOM row underneath the TOP row corner where it belongs with the matching face colors. Use the algorithm as many times as needed until the corner is correctly place. Repeat the steps for each corner until all four corners are in the correct places. REVIEW FROM THE WHITE CORNERS To get the WHITE corners matched with the correct faces: Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

5. HORIZONTAL Horizontal is the name that describes when a line (or row) is parallel to the horizon. When looking at the cube, a horizontal line is parallel to the BOTTOM or TOP row of the cube THE MIDDLE LAYER IS HORIZONTAL HORIZONTAL LINE Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

6. VERTICAL Vertical is the name that describes when a line (or row) is perpendicular to the horizon. When looking at the cube, a vertical line is parallel to the RIGHT or LEFT row of the cube. THE BLUE MIDDLE ROW IS VERTICAL VERTICAL LINE Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

7. Find an edge on the UP face that is NOTYELLOW. • Match the FRONT face of the edge to the center piece of the same color so that there is a vertical middle line of all one color on the FRONT Face of the cube. • Look at the TOP Face of the edge • Decide whether the edge needs to move clockwise or counter-clockwise: With the WHITE Face on the DOWN Face and the YELLOW Face on the UP Face: Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

8. If the TOP Face color belongs on the RIGHT Face of the cube: • If the TOP Face color belongs on the LEFT Face of the cube: With the WHITE Face on the DOWN Face and the YELLOW Face on the UP Face: Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

9. Find another edge on the UP face that is NOTYELLOW. • Match the FRONT face of the edge to the center piece of the same color so that there is a vertical middle line of all one color on the FRONT Face of the cube. • Look at the TOP Face of the edge: • If the TOP Face color belongs on the RIGHT Face of the cube: • If the TOP Face color belongs on the LEFT Face of the cube: With the WHITE Face on the DOWN Face and the YELLOW Face on the UP Face: Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

10. If there are no more NON- YELLOW edges to work with, use one of the algorithms to place a YELLOW edge on the RIGHT or LEFT face where there is an unsolved edge. • By moving a YELLOW edge to an unsolved place in the middle row, the NON- YELLOW edges will shift to give you the opportunity to work with a NON- YELLOW edge. • If you accidentally move an edge piece to the wrong place (do one of the following): • Leave it there and continue working with the other edge pieces • You can “undo” the move by inverting (doing the opposite) each ¼ turn and performing the algorithm inverted and backwards TROUBLESHOOTING Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

11. Leave it there and continue working with the other edge pieces • Eventually, you will find the correct edge piece and place it in its correct place. • The misplaced edge piece will be moved and available to move to its correct place. TROUBLESHOOTING Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

12. You can “undo” the move by inverting (doing the opposite) each ¼ turn and performing the algorithm inverted and backwards • For example, if you moved the TOP row middle piece clockwise, you used the algorithm: • To “undo” the move, you would invert the moves and reverse the algorithm: TROUBLESHOOTING Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

13. GOAL:The Middle Layer Examine your Rubik’s Cube. The goal of this stage is to get the Middle Layer (the horizontal middle row) with the WHITE Face as the DOWN Face. Does your Rubik’s Cube look like this? Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

14. Congratulations! Congratulations! Congratulations! Congratulations! Congratulations! Congratulations! You have achieved The Middle Layer Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

15. Find an edge on the UP face that is NOTYELLOWon the UP or FRONT face. Match the FRONT face of the edge to the center piece of the same color so that there is a vertical middle line of all one color on the FRONT face of the cube. Look at the TOP face of the edge: If that color belongs on the RIGHT face (clockwise) of the cube: If that color belongs on the LEFT face (counter-clockwise) of the cube: Repeat the instructions until the horizontal middle line of each face has been solved. Make sure the WHITE cross remains intact each time you reposition a WHITE corner. REVIEW To get the Middle Layer: Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

16. To “undo” a move on the Rubik’s Cube, you do the opposite of what was done. • In math, the same idea applies. • To do the opposite of addition, you subtract. • To do the opposite of subtraction, you add. • For example: • If you have 2 Rubik’s Cubes and you add 3 more, you will have 5 Rubik’s Cubes all together. • If you subtract, or take away 3 Rubik’s Cubes, you will be left with the original 2 apples. Lesson Extension How does this lesson apply to math? Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

17. For example: • The opposite of a positive is a negative. • When using integers on a number line, adding opposites together will result in 0. • By adding +4 and -4, the result is 0. -4 -3 -2 -1 0 1 2 3 4 Lesson Extension How does this lesson apply to math? Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

18. For example: • By subtracting 5 from both sides of the equal sign, the problem was balanced and solved. • To get x alone, the opposite operation was used. • The opposite of +5 is -5. • x + 5 = 11 • -5 -5 • x = 6 Lesson Extension How does this lesson apply to math? Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

19. When the BOTTOM and Middle rows are complete, the cube is two-thirds solved. • When the WHITE face is the DOWN face and the YELLOW face is the UP face, there are three horizontal rows – TOP, MIDDLE, BOTTOM. • Each row has 12 squares around. • Total that is 36 squares around. • If two rows are complete, then 24 squares are complete. • 24 over 36 can be simplified to 2 over 3. ⅔ Lesson Extension How does this lesson apply to math? Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab

20. Who was the inventor of the Rubik’s Cube? Where was he from? Erno Rubik; from Hungary Review from Previous Lesson Lesson Focus Review from this Lesson Lesson Extension Rubik’s Q Lesson Vocab