• Ones place: The digit shows how many ones are in the number.
  Example: In 247, the 7 means 7 ones.

• Tens place: The digit shows how many groups of ten are in the number.
  Example: In 247, the 4 means 40 (4 tens).

• Hundreds place: The digit shows how many groups of one hundred are in the number.
  Example: In 247, the 2 means 200 (2 hundreds).

Directions: On a piece of paper write the problems out and solve. Show your work and thinking through expanded form or using base 10 method or model.

Problems:

• What is the value of the 8 in the number 486?

• In the number 739, what digit is in the tens place?

• Write the number that has 5 hundreds, 3 tens, and 2 ones.

• What is the value of the 4 in the number 4,215?

• In the number 692, which digit is in the ones place?

• Write 643 in expanded form.

• Which number has a 7 in the tens place?
  a) 372
  b) 705
  c) 517

• The number is 825. How many hundreds are in this number?

• Fill in the blank:
  4 hundreds + 2 tens + 9 ones = ________

• A number has 9 ones, 4 tens, and 6 hundreds. What is the number?

Our number system is called base 10 because it is built on tens. Every time we collect 10 of something, we make a new group in the next place value.

How It Works with Blocks:

• Ones blocks (small cubes): Each cube stands for 1.

• Tens rods (a stick made of 10 cubes): Each rod stands for 10 ones.

• Hundreds flats (a big square of 100 cubes): Each flat stands for 100 ones or 10 tens.

  Example:

  If we have the number 243:

  • 2 hundreds = 200 (two flats)

  • 4 tens = 40 (four rods)

  • 3 ones = 3 (three cubes)

  So, 243 = 200 + 40 + 3.

  
  

  Why It’s Important:

  The base-10 system helps us:

  • Break apart numbers into hundreds, tens, and ones.

  • Build numbers using blocks, drawings, or place value charts.

  • Understand that each place is 10 times bigger than the place to its right.