Adding Decimals by rounding and compensating

For maths we are learning how to add decimals by rounding and compensating. We need to round to the nearest whole number. The example above shows I have subtracted .3 from 8.3 to make 8 the whole number, then compensated by adding .3 to 2.6 to make 2.9 then adding 8 + 2.9 to get 10.9