N3YouTube

(おれ)計算(けいさん)得意(とくい)で、数学(すうがく)先生(せんせい)になりたいと(おも)って勉強(べんきょう)している。

I am good at calculations and I am studying because I want to become a math teacher.
75 words
(おれ)計算(けいさん)得意(とくい)なんだよ計算(けいさん)得意(とくい)なさあ

(おれ)

N5
pn
I; me(rough or arrogant)

N5
suf
-ness(nominalizing suffix indicating degree or condition)
prt
indicates assertion(sentence end, mainly masc.)

(けい)(さん)

N3
n, vs, vt
calculation; reckoning; count
vt, vs, n
forecast

(とく)()

N4
n, adj-na, adj-no
satisfaction; pride; triumph; elation
n, adj-na, adj-no
one's strong point; one's forte; one's specialty

N5
prt
don't(prohibitive; used with dictionary form verb)
prt
do(imperative (from なさい); used with -masu stem of verb)

N5
int
yes; yeah; uh huh
int
huh?; what?

N5
cop, cop-da
be; is(plain copula)
aux-v
did; (have) done(た after certain verb forms; indicates past or completed action)

N5
adj-ix
good; excellent; fine; nice; pleasant; agreeable(also written 良い, 好い and 善い)
adj-ix
sufficient; enough; ready; prepared

さあ

N5
int
come (on); come now; come along; here(used to urge or encourage others)
int
all right; right; okay; now; here goes(indicates resolve)
すげーじゃんなんでそもそも計算(けいさん)得意(とくい)

すげー

N5
exp, int
incredible; unbelievable; terrific; impressive

じゃん

N5
prt
isn't it?; don't you think?; right?; surely; come on(used to state something assertively; orig. from じゃないか)

なんで

N5
adv
why?; what for?
adv
how?; by what means?

そもそも

N2
n, adv
in the first place; to begin with; from the start; originally; ab initio
conj
after all; anyway; actually; well, ...; ... on earth (e.g. "what on earth?"); ... in the world (e.g. "why in the world?")(used when bringing up something already mentioned)

(けい)(さん)

N3
n, vs, vt
calculation; reckoning; count
vt, vs, n
forecast

(とく)()

N4
n, adj-na, adj-no
satisfaction; pride; triumph; elation
n, adj-na, adj-no
one's strong point; one's forte; one's specialty

N5
prt
don't(prohibitive; used with dictionary form verb)
prt
do(imperative (from なさい); used with -masu stem of verb)
(じつ)はね

実は

N3
adv, exp
as a matter of fact; by the way; to tell you the truth; to be honest; frankly

N5
prt
right?; isn't it?; doesn't it?; don't you?; don't you think?(at sentence end; used as a request for confirmation or agreement)
int
hey; say; listen; look; come on
数学(すうがく)先生(せんせい)になろうと(おも)ってて色々(いろいろ)勉強(べんきょう)

(すう)(がく)

N4
n
mathematics

N5
prt
indicates possessive(occasionally ん, orig. written 乃 or 之)
prt
nominalizes verbs and adjectives

(せん)(せい)

N4
n
teacher; instructor; master
n, n-suf
sensei; title or form of address for a teacher, master, doctor, lawyer, etc.

N5
prt
at (place, time); in; on; during
prt
to (direction, state); toward; into

なろう

N4
v5r, vi
to become; to get; to grow; to turn; to reach; to attain
v5r, vi
to result in; to turn out; to end up; to prove (to be)

N5
prt, conj
if; when
prt, conj
and

(おも)って

N3
v5u, vt
to think; to consider; to believe; to reckon(想う has connotations of heart-felt)
v5u, vt
to think (of doing); to plan (to do)

いて

N5
suffix
indicates continuing action (to be ...ing)

(いろ)(いろ)

N4
adj-na, adj-no, adv, adv-to, n
various; all sorts of; variety of
n
various colors (colours)

(べん)(きょう)

N4
n, vs, vt
study
n, vs, vi
diligence; working hard

して

N2
vs-i
to do; to carry out; to perform
vs-i
to cause to become; to make (into); to turn (into)
てんだよねまあ数学(すうがく)先生(せんせい)だろうと(おも)って

N5
int
yes; yeah; uh huh
int
huh?; what?

だよね

N5
exp
it is, isn't it?; I know, right?; innit?

まあ

N3
adv
just (e.g. "just wait here"); come now; now, now(when urging or consoling)
adv
tolerably; passably; moderately; reasonably; fairly; rather; somewhat

(すう)(がく)

N4
n
mathematics

N5
prt
indicates possessive(occasionally ん, orig. written 乃 or 之)
prt
nominalizes verbs and adjectives

(せん)(せい)

N4
n
teacher; instructor; master
n, n-suf
sensei; title or form of address for a teacher, master, doctor, lawyer, etc.

だろう

N5
cop, cop-da
be; is(plain copula)
aux-v
did; (have) done(た after certain verb forms; indicates past or completed action)

N5
prt, conj
if; when
prt, conj
and

(おも)って

N3
v5u, vt
to think; to consider; to believe; to reckon(想う has connotations of heart-felt)
v5u, vt
to think (of doing); to plan (to do)