2021 AMC 10 A reflection notes from E, a 7th grader

#12 wrong. #17–19 ran out of time but solved afterward. #21 took too much time but was solvable. 

#22–25 not attempted. The others all right. Good try. :) :) :) 

Main focus: improve pacing and find more efficient approaches.

Reviewed #3, #6, #8, #12, #14, #16, #19, and #21. 

She can solve these problems; our focus was on whether there are cleaner, 

faster, and more efficient approaches.

2022 AIME I reflection notes from H

2022 AIME I — Reflection Notes from H

Attempted: #4–12

Correct: #4–9, #11–12

Had trouble / wrong: #10

Need Review / Unclear:

#8 – Diagram got way messy. Tried to use side-length scaling to get the box/answer, but it didn’t work.

#10 – Not sure how to visualize; was difficult with a plane not totally perpendicular.

2021 AIME 1 reflection notes from H

AIME — Reflection Notes from H

Did 8 to 15 Incorrect / wrong: #9, #13, #15

Need Review / Unclear:

#9 – Not able to use similar triangles.
#13 – Totally confused; I tried PUP.
#15 – Not sure how to solve a quartic equation (x⁴).

2020 AIME I reflection notes from H

2020 AIME I - Reflection Notes from H

Did: #8–15

Had trouble / wrong: #12, #15

Need Review / Unclear:

#12 – Don’t know LTE, but I was very close to solving this using the binomial theorem.
#15 – Wasn’t able to see the symmetry: the circumcircle of IBC (with the orthocenters) is a reflection of the circumcircle of ABC.

2019 AIME I reflection notes from H

2019 AIME I — Reflection Notes from H

9 out of 15, 2 didn't finished were very close. like to know if there is better strategies for some problems.

Quick stats
• #1–5 took about 22.5 min total.
• #6 took about ~20 min (time sink).

My answers (as written)
#1: 342
#2: 029
#3: 120
#4: 122
#5: 252
#6: 090
#7: 880
#8: (very close — not finished)
#9: (wrong / crossed out)
#10: 357 (marked “silly”)
#11: ✓ (got it, but messy)
#12: (very close — basically solved but error)
#13: (basically solved, but used the wrong operation / wrong term; didn’t finish)
#14: 097
#15: (did not attempt)

Had trouble / wrong

#6 – Tried using binomial expansion, but it became too much computation (huge time sink).
#9 – Went nowhere / ended up crossing it out.
#10 – Silly mistake (need to slow down + verify).
#13 – Basically solved, but multiplied/used the wrong thing (wrong term like a_i) and didn’t finish.

Very close / almost

#8 – Very close (need to push to the finish next time).
#12 – Basically solved, but made an operation mistake (multiplied when I shouldn’t / wrong step).

Need review / improve

#11 – Got it, but I couldn’t visualize well, and the computations got messy.
#14 – Some algebra at the end felt annoying; practice finishing cleanly under time.

Not attempted

#15 – Did not attempt.