U256::from(add_amount.to_owned().saturated_into::<u128>())
    .saturating_mul(total_reward.to_owned().saturated_into::<u128>().into())
    .checked_div(initial_total_shares.to_owned().saturated_into::<u128>().into())
    .unwrap_or_default()
    .as_u128()
    .saturated_into()
