Multiply by 49 No Calculator Shortcut

we start at the top and write 4 and add 5 for every line we go down:
49 * 1 = 4
49 * 2 = 9
49 * 3 = 14
49 * 4 = 19
49 * 5 = 24
49 * 6 = 29
49 * 7 = 34
49 * 8 = 39
49 * 9 = 44
49 * 10 = 49

Next, we start the bottom of the list. add on a 0 at the end, and for each line we go up, we add 1 more from the previous line
49 * 1 = 49
49 * 2 = 98
49 * 3 = 147
49 * 4 = 196
49 * 5 = 245
49 * 6 = 294
49 * 7 = 343
49 * 8 = 392
49 * 9 = 441
49 * 10 = 490