1. Not silver. The U.S. never minted a silver penny. It would have more than a dime's worth of silver in it.
2. Not "S". The first S-mint pennies were made in 1908.
Please post a new question with a more complete description of the coin.
Yes the 1970 penny is real silver and is worth keeping or even selling
US cents have never been made of silver, not even in the 1800s.
It is worth a penny
The phrase means that something is very expensive. The origin comes from a gold penny that was minted in the 1200's that was worth 20 silver pennies. Because it was gold, it was a pretty penny, and if it cost a pretty penny, it was expensive indeed.
1900 is not a rare date for Morgan Dollars. In average circulated condition, it's worth $8-$10. If it has an "S" mintmark on the back (above the "DO" in DOLLAR), it will be worth a couple dollars more.
A 1900 Morgan dollar (the phrase E Pluribus Unum by itself doesn't specify coin type or denomination) is worth around $24-30 depending on condition. If it's a 1900-S, then it's worth a little more.
If it's dated 1900, then it's a Morgan silver dollar. It's worth at least $20 or so in worn condition, and closer to $40 in uncirculated condition. If you have a 1900-S Morgan, the value is a bit higher.
The value of a 1912 s penny depends greatly on the condition of the penny. In poor condition, it is only worth a penny, but in very good condition it may be worth $10 or more.
$10,000
A 1920's Lincoln penny in good condition can be worth anywhere from 5 dollars to 30 dollars. This is a old penny.
It depends on how you define value. Do you mean monetary value or personal value. Pennies were very valuable in the 1900's but they were only worth one cent.
5 dollars