4.NBT.A.1
Recognize that in a multi-digit whole number, a digit in one place represents ten times what it represents in the place to its right. For example, recognize that 700 ÷ 70 = 10 by applying concepts of place value and division.
Multiply and divide by 10. Relate numbers such as 800 and 80 by noticing that 800 is 10 times 80. Identify how place value changes when multiplying by 10. For example, starting with 63, if we multiply by 10, the 3 ends up in the ____ place value.