An earlier puzzle was CUP + CUP = PINT, now we have the follow up! PINT + PINT = QUART
This is doable by hand! Solutions are below the image.
SPOILER SOLUTIONS!
| PINT_first | PINT_second | QUART_third |
|---|---|---|
| 6390 | 6390 | 12780 |
| 6790 | 6790 | 13580 |
| 6920 | 6920 | 13840 |
| 7280 | 7280 | 14560 |
| 7290 | 7290 | 14580 |
| 7640 | 7640 | 15280 |
| 7690 | 7690 | 15380 |
| 7820 | 7820 | 15640 |
| 7920 | 7920 | 15840 |
| 7930 | 7930 | 15860 |
| 8270 | 8270 | 16540 |
| 9230 | 9230 | 18460 |
| 9270 | 9270 | 18540 |
| 9320 | 9320 | 18640 |
| 9360 | 9360 | 18720 |