There are other associations which will help to fix the digits and their corresponding sounds in mind.
T is selected for 1 because both are made with one down stroke. One down stroke with a short cross stroke makes the T.
N, for 2 is the same, two down strokes make the N.
M represents the 3 and there are three down strokes in the written M.
R is the last letter and principal sound in the word fouR, which has four letters.
L is the Roman numeral representing 50, similar to 5.
F selected for 8 has the two loops, when written.
C is the first letter and sound of the word Cipher.
Acquaint Yourself With the Code
Work entirely by SOUND, remember it is the sound M in the word Make that has the value of 3, and if not sounded would have no value. Become familiar with these ten digit sounds so that when you see a digit you can immediately recall the sound. Then practice sounding words and telling the number value of each SOUND in the word. Pay no attention to the letters; only the sounds have value.