8 thoughts from Singapore

At the International Conference on Mathematics Education held in Hamburg, Germany in July 2016, Berinderjeet Kaur gave a presentation on mathematics classrooms studies.   She is the foremost authority in Singapore on mathematics education.    At minute 38:45 came this observation from data:
about the student perspective on good lessons.

Findings: close-up lens

Analysis of the interview transcripts revealed
that students deemed a mathematics lesson as a
good one when some of the following
characteristics were present.

Teacher

(1) explained clearly the concepts and steps
    of the procedure

(2) made complex knowledge easily assimilated
    through  demonstrations, the use of
    manipulatives, and real life examples.

(3) reviewed past knowledge

(4) introduced new knowledge

(5) used student work/group presentations
    to give feedback to individuals or
    the whole class

(6) gave clear instructions related to
    mathematical activities for in class
    and after class work.

(7) provided interesting activities for
    students to work on individually
    or in small groups

(8) provided sufficient practice tasks for
    preparations towards examinations

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In a lesson there may be more than one instructional 
objective but the structural patterns of the lesson 
are done in sequence.
[[at minute 29 of video]] Instructional approaches may involve
D - Whole class demonstration (aimed to develop 
    students' understanding of mathematical skills
    and concepts)
S - Seatwork
R - whole class review of student work
M - Miscellaneous -  managerial and administrative 
Q - Group Quiz
T - Test
[D] [S] [R] were present in all 3 classrooms observed

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Singapore bases their program on a combination of Traditional
Instruction with Direct Instruction and then builds from this 
to Teaching for Understanding.