What is the sum of X+XX+XXX+XXXX?

Read also:

• Why do Darwin atheists not like facts of Genesis? I’ve noticed they block and dismiss everything a person states. Is that how science works to hide when a truth comes at them?
• What are some effective strategies for getting more upvotes on Quora?
• Why do gun lovers think their right to own a weapon supercedes everyone else's right to be safe and not be shot?
• What discoveries in AI research have changed our understanding of intelligence evolution?
• What are mean nicknames to call my sister? She is always so mean to me.
• What baseball stories from the early days of the sport seem too bizarre to be true?
• What's your review of "The Queen Who Ever Was," Episode 8 of Season 2 of 'House of the Dragon' (spoilers)?
• Scientists create a two-dimensional carbon material eight times stronger than graphene - Earth.com
• I live in Massachusetts. Are there any resources here for people that are being harassed by voice to skull, etc.?
• How can people balance religious beliefs with seeking professional mental health care?