1.6 - 3 = 311 - 7 = 415 - 6 = 913 - 9 = 48 - 2 = 6
2.8 - 1 = 710 - 6 = 47 - 5 = 23 - 3 = 012 - 5 = 7
3.6 - 1 = 56 - 2 = 49 - 3 = 613 - 4 = 912 - 8 = 4
4.13 - 6 = 711 - 9 = 212 - 7 = 515 - 8 = 711 - 2 = 9
5.6 - 5 = 17 - 4 = 37 - 3 = 49 - 3 = 66 - 3 = 3
6.12 - 3 = 918 - 9 = 911 - 9 = 29 - 6 = 310 - 5 = 5
7.14 - 5 = 910 - 3 = 73 - 1 = 212 - 7 = 58 - 4 = 4
8.6 - 5 = 114 - 6 = 810 - 8 = 28 - 3 = 517 - 8 = 9
9.7 - 1 = 65 - 4 = 12 - 1 = 117 - 9 = 812 - 8 = 4
10.8 - 3 = 59 - 9 = 06 - 4 = 25 - 4 = 111 - 5 = 6
11.18 - 9 = 912 - 4 = 810 - 7 = 39 - 8 = 115 - 6 = 9
12.14 - 8 = 64 - 1 = 312 - 5 = 75 - 3 = 212 - 9 = 3
13.3 - 0 = 35 - 1 = 44 - 3 = 113 - 5 = 84 - 3 = 1
14.10 - 3 = 710 - 2 = 83 - 2 = 110 - 4 = 614 - 9 = 5
15.8 - 1 = 75 - 1 = 415 - 7 = 813 - 4 = 916 - 7 = 9
16.6 - 1 = 511 - 8 = 34 - 2 = 27 - 4 = 313 - 8 = 5
17.17 - 8 = 98 - 5 = 38 - 6 = 213 - 6 = 79 - 7 = 2
18.14 - 5 = 910 - 5 = 57 - 1 = 610 - 1 = 97 - 3 = 4
19.7 - 6 = 19 - 4 = 513 - 8 = 511 - 2 = 917 - 9 = 8
20.4 - 1 = 39 - 5 = 43 - 2 = 112 - 9 = 35 - 2 = 3

answers to this test: jakeholland.net/multest.php?vals=0-9&op=sub&seed=1592112091&answer

random multiplication test: /multest.php?vals=0-9&op=mul
random division test: /multest.php?vals=0-9&op=div
random addition test: /multest.php?vals=0-9&op=add
random subtraction test: /multest.php?vals=0-9&op=sub