Confused With Census Records

[Julz83]

I'm a bit confused with some census records.

Mary Foreman, my 3rd Great Grandmother, was born 1830 in Longhoughton.
She married John Johnston Robinson (1822-1885)
They had 5 children.

On the 1841 Census Mary is listed at the age of 11 living with the rest if the family, her parents William Foreman, 65 and Elizabeth Foreman, 55, her siblings are
William 25 (b.1816)
Eleanor 20 (b.1821)
James 20 (b.1821)

Now on the 1851 Census Mary is there age 21 which is fine, but the others listed are
Elizabeth 63
James 39
Robert 27
Henry 25
William Willoughby 8 (Grandson)

William and Eleanor may have moved out, I haven't looked into that yet, but, how is James 39? And why weren't Robert and Henry on the previous Census. I also have no idea about William Willoughby stated as Grandson?

Can anyone shed any light.

[dawnsh]

ages of those over 15 were rounded down which might account for some of the discrepancy, other than that the enumerator may have made a mistake.

Have you found baptisms for the children so you have a better idea of their actual ages?

[groom]

Looking at the actual image for 1851, James could be 29, with the line drawn across it making it look as if it's 39.

[keyboard86]

Hi could Robert & Henry have been with their Grandmother/Aunt in 1841?

Jane Foreman 68
Robert 17
Henry 15
Residing at Longhoughton Village
Census ref HO107/819/ 19/17 / 9
Keyboard86

[groom]

I also have no idea about William Willoughby stated as Grandson?

I would say that William is Eleanor's son

Marriages Jun 1843   
Foreman    Eleanor       
Willoughby    John William       
 Alnwick    25   209

[avm228]

James Foreman, son of William and Elizabeth, was baptised at Longhoughton on 2 July 1821.

[avm228]

Eleanor's baptism date was 22 September 1816.

[avm228]

William Foreman was baptised on 1 July 1816.

[avm228]

Robert Foreman was baptised on 2 July 1827.