All About Three-Digit Numbers

Explicit Instruction/Teacher modeling

• Explain to students that three-digit numbers can be separated into different place values. These place values are the ones, tens, and hundreds.
• Project the Place Value Mat: Three-Digit Numbers on the whiteboard. Record the number 285 on the place value mat, separating each digit into the correct column. Tell the students that a digit is a number that has its own place value. Reinforce that the number 285 has three digits. That it why its called a three-digit number.
• Ask students to identify the number of ones, tens, and hundreds in the number 285.
• Use base-ten blocks to show your students a visual representation of 285.
• Explain to the students that next they will practice writing this number in words. Explain that when writing in words we move from left to right.
• Model how to record the number "two hundred eighty five."

Guided Practice

• Pass out the Place Value Mat: Three-Digit Numbers to each student. Give students an example number, such as 458.
• Guide students to fill in the number on their place value mats as you record the number on yours.
• Sketch base-ten blocks to show the number 458, or use tangible base-ten blocks. Remind students that small boxes represent the ones, tall rectangles represent the tens, and squares represent the hundreds.
• Provide students with access to the base-ten blocks, or encourage them to use the sketching technique to show the number in a visual form.
• Explain that the class is now going to practice the written form of the number. Remind students that we read the words from left to right.
• Use a number anchor chart or word bank to display the different forms of a number to help your students remember (e.g. write the words one through ten on the chart or in the word bank).
• Give your students another example number and ask them to fill in the place value mat and record the number in written form.
• Challenge students to identify whether more or less base-ten blocks will be needed for each additional number.

Independent working time

• Provide students with two more three-digit numbers. Write down the following steps on the whiteboard:
  1. Write the number down on the place value mat.
  2. Sketch the number using base-ten blocks or create the number using base-ten blocks.
  3. Write the number in written form.
• Remind students to use the anchor chart for support.