Hi christinarosetti
Hard to know what to suggests as you didn't provide age of your DC is or year - but I think what your DC may mean (especially if KS1) is that the teacher is making a grid for different numbers - units/ tens/ hundreds
So let's say you're DC is adding 16 + 17
Draw a horizontal line and then a perpendicular line through it extending down - so it's like a long t.
The left column has the heading TENS and the right column has the heading UNITS.
Now insert 16 and 17.
TENS UNITS
1 6
well that's a bit crazy - you can't have 13 in the units column - so leave the 3 (units) and carry the ten to the tens column
TENS UNITS
2 3
you then have 3 tens and 3 units otherwise known as 33.
Teacher may also be deconstructing numbers using a table of 3 rows and 4 columns :
so 341 + 537
HUNDREDS Row - Column 1 write down 300/ Column 2 write down 500
TENS Row - Column 1 write down 40 and column 2 wirte down 30
UNITS row - column 1 write down 1 and column 2 write down 7
Now add two columns together for each row and write the answer in the 4th column of the row
HUNDREDS: 300 + 500 = 800
TENS: 40 + 30 = 70
UNITS: 1 + 7 = 8
Now add up the numbers in the 4th column:
800 + 70 + 8 = 878
These are my ideas about it off the top of my head.
If these make sense for your DC great - if not my advice is ask the teacher to show you a quick example of the method so you can help at home or check school website for the numeracy policy (although saying this I know our school still after 6 years of asking refuses to develop one).
HTH