10
s, z, soft c z is the first letter of zero. The others have a similar sound.
21
d, t, th
d and t have one downstroke and sound similar (notice the tip of your tongue as you say them).
43
m has three downstrokes, also m looks like a 3 lying on its side.
54
r the last letter of four, also 4 and R are almost mirror images of each other.
65
L is the Roman numeral for 50.
76
j, sh, soft ch, dg, zh, soft g
a script j has a lower loop like 6. These letters also have a 'whistle-like' sound, and 6 looks like a whistle.
87
k, hard c, hard g, q, qu
capital K contains two 7s (on their sides, back to back).
98
v, f
think of v as in a V8 motor. f sounds similar (notice how your teeth touch your lips for both).
109
b,p
p is a mirror-image 9. b sounds similar and resembles a 9 rolled around (also notice how your lip movement is the same when pronouncing these letters.)