Addition Level 27: 4d + 4d (ones carry). large answer-window addition. 1. Fill thousands3648 + 2579Step 1: Fill thousands3648plus25795raw windows3 + 2 = 5 then release 5running strip5Thousands window: 3 + 2 = 5. Hold 5; wait for carry from the next window.2. Fill hundredsStep 2: Fill hundreds3648plus2579511raw windows6 + 5 = 11 then keep 1; carry waitsrunning strip51Hundreds window: 6 + 5 = 11. Hold raw 11; settle carry later.3. Fill tensStep 3: Fill tens3648plus257951111raw windows4 + 7 = 11 then keep 1; carry waitsrunning strip511Tens window: 4 + 7 = 11. Hold raw 11; settle carry later.4. Fill onesStep 4: Fill ones3648plus25795111117raw windows8 + 9 = 17 then keep 7; carry waitsrunning strip5117Ones window: 8 + 9 = 17. Hold raw 17; settle carry later.5. Settle carryStep 5: Settle carryKeep ones; carry moves left.raw windows5 | 11 | 11 | 17settled digits6 | 2 | 2 | 7answer 6227Settle raw 5 | 11 | 11 | 17 into 6227; keep ones and move carry left.