Room 10, Silver task, Adding numbers,

We have been learning to add numbers and place values, I found this hard on the trickier ones because of the 19 18 16 17 those numbers I was stuck on. I feel like I want to practice this maths activity until I have the answers in my head. so i found this activity really really hard, the strategy I got to get these answers right was 51+18= so then I put 50 in the  tens place and the 1 in the ones place.