GRADE 2 - MATH / ALGEBRA, Find the missing part

Younger students often have difficulty with algebra problems.  For example  3 +  ___  =  10.

so I use a technique which I call the "Build the Ladder" to help them discover the answer.

Students place the number of blocks down that they know in the "I have" section.  In this case 3 blocks.
They right the total number that they have to count up to in the box which is labeled "Stop" to remind them to stop counting.

Here you see the rungs of the ladder drawn on as the student counts 1,2,3 (from the blocks)......4,5,6,7,8,9,10 (on the ladder).

The student then counts the number of rungs on the ladder to find the missing part....7.
I'm a big fan of the white board and my students love working on them too!