$$0.065 kg$$ and $$4023 gm$$
$$= 0.065 × 1000 gm + 4023 gm$$
We get,
$$= 65 gm + 4023 gm$$
$$= 4088 gm$$
Now, converting into kilogram, we get
$$= 4088 / 1000$$
$$= 4.088kg$$
$$\therefore$$ The addition of $$0.065 kg$$ and $$4023 gm$$ is $$4.088 kg$$