To determine what Albert did wrong in calculating the sum of 346 + 51, let’s add the numbers correctly:
346
+ 51
______
Starting from the rightmost column:
- Units place: 6 (from 346) + 1 (from 51) = 7
- Tens place: 4 (from 346) + 5 (from 51) = 9
- Hundreds place: 3 (from 346) + 0 = 3
So, the correct sum is:
346
+ 51
______
397
Since 397 is the correct sum, and Albert got 856, it seems he likely made a mistake in his addition rather than multiplying or misaligning digits. It seems he may have made an error when adding the tens (4 tens + 5 tens = 9 tens) but ended up with a wrong total.
The most accurate response seems to be: "Albert made a mistake when adding 4 tens + 5 tens."