my follow up

Walt: Use two strategies to solve number problems

one thing that I learnt from this strategy was 27 + 47   = 74   because
20 + 40 = 60 then 7 + 7 = 14
60 +14 = 74 .

Also my other strategy was 584 + 800 = 1384
1384 + 40 = 1424 then 1424 + 5 = 1429