Explain how to use the combine place values strategy to find 223-119

Combine place value strategy is useful if you try to subtract a number with bigger digits from a number with a smaller digit in the same place... such as now, where 3 is smaller than 9 in the ones place. 

Then we can combine two place values: 23 and 19 and subtruct those. 23-19 is 4 (you can just count up from 19 to 23), so you know that the two will give  the result of 04, and then you can proceed to the left: 2-1=1. 

so the final result will 104.

Hope I helped:P 

Are you asking for 6 or 15?