Addition Level 3: 2d + 1d (with carry). answer-window addition. 1. Fill tens48 + 7Step 1: Fill tens48plus74raw windows4 + 0 = 4 then release 4running strip4Tens window: 4 + 0 = 4. Hold 4; wait for carry from the next window.2. Fill onesStep 2: Fill ones48plus7415raw windows8 + 7 = 15 then keep 5; carry waitsrunning strip45Ones window: 8 + 7 = 15. Hold raw 15; settle carry later.3. Settle carryStep 3: Settle carryKeep ones; carry moves left.raw windows4 | 15settled digits5 | 5answer 55Settle raw 4 | 15 into 55; keep ones and move carry left.
