# Find a missing number in this 28x21 grid

355|066|677|855|677|081|044|855|355|062|216|677|216|855|224|044|034|046|051|677|355|264|044|046|044|351|886|043
043|044|886|357|886|352|225|357|043|222|993|001|233|968|046|225|062|041|351|886|043|227|359|233|855|357|677|046
359|216|255|045|255|968|233|045|359|264|678|238|506|222|062|233|222|066|034|255|359|233|855|224|968|046|886|041
855|993|216|358|216|051|224|358|855|227|244|357|385|053|222|224|264|044|046|216|855|224|051|041|992|046|255|066
357|678|993|081|993|351|062|081|357|966|265|045|855|253|503|062|227|855|357|062|357|062|357|066|868|044|216|044
045|244|678|062|992|034|677|352|966|224|216|358|357|216|291|473|966|357|045|222|676|222|034|044|993|062|062|045
358|265|244|222|868|216|886|357|509|965|886|081|045|993|679|507|677|045|358|264|244|034|224|216|855|227|244|358
081|264|265|264|244|993|255|045|504|856|058|224|225|062|041|351|886|043|081|227|265|504|253|255|357|081|678|081
352|227|064|227|061|678|216|358|091|692|062|357|081|244|993|216|044|081|855|966|357|357|503|291|351|886|043|855
968|966|970|966|242|244|993|855|964|680|222|045|352|265|351|993|225|352|357|677|216|045|062|679|473|???|233|357
051|677|992|267|246|265|062|357|876|507|264|358|255|357|081|678|233|081|045|255|993|355|222|044|502|380|224|045
351|886|053|001|375|357|222|045|962|595|044|066|677|855|352|244|224|046|358|216|678|043|264|225|592|598|967|358
034|255|253|238|501|045|264|358|254|685|225|044|886|357|968|265|062|041|081|993|244|359|227|233|509|058|380|081
046|473|503|506|216|357|227|081|965|252|233|216|255|045|051|233|255|357|081|678|265|855|966|224|216|081|855|352
041|502|291|385|993|045|966|352|856|249|224|993|216|358|351|224|993|062|062|046|967|357|677|062|993|062|062|868
066|592|679|355|678|358|677|677|692|676|062|678|993|081|034|062|044|227|855|357|503|051|046|359|265|081|222|355
044|968|034|043|244|046|355|886|680|256|224|244|678|062|351|886|043|357|062|506|291|473|041|351|244|352|264|043
225|051|046|359|265|041|043|255|507|380|592|504|964|962|965|692|061|246|501|001|679|502|066|034|233|968|227|359
233|351|041|678|233|081|045|255|993|598|509|091|876|254|856|680|242|375|267|238|051|046|359|265|224|051|966|855
224|034|066|244|224|046|358|216|678|255|045|255|968|233|045|359|233|222|066|034|255|359|233|968|046|351|046|358
062|046|044|265|062|041|081|993|244|216|358|216|051|224|358|855|224|264|044|045|216|855|224|051|041|034|041|081


What is the missing number (denoted by ???) in this 28x21 grid?

• Is this an original puzzle? Oct 24, 2021 at 16:51
• yes, it is original Oct 25, 2021 at 8:20