## Lesson: Place Value to 1,000 Introducing the Concept

Before beginning place value to 1,000, review place value through 99. If the children spend some time reviewing, the transfer of knowledge to 1,000 will be much easier. Take time to practice many groupings of two-digit numbers, using the language of place value.

Materials:84 connecting cubes, tens and ones mat for each child or pair of children

Preparation:Give a tens and ones mat to each child. Prepare a chart of number words. One column should include the number words one to nine, a second column ten to ninety by tens, and a third column, eleven to nineteen. Place it so children can refer to it.

Prerequisite Skills and Concepts:Children should know how to count to 100. They should be familiar with number words and what they look like when written.

Give each child (or pair of children) 26 cubes.

• Ask: How many cubes do you have?
Children should count and say that there are 26 cubes.
• Say: Put away those cubes. I'm going to give you some more cubes.
Give children 26 more cubes.
• Say: First make as many groups of ten as you can.
• Ask: How many groups of ten can you make?
Children should say they have 2 groups of tens, or 2 tens.
• Ask: How many tens and ones do you have? (2 tens and 6 ones)
How many cubes are there? (26)
Do you remember how many cubes you counted before? (26)
Are there the same number of cubes in both groups?
Children should say that the two groups have the same number of cubes.
• Ask: Does it change the number when you group the tens?
Children should say that the number is the same whether you count them or group them and count them by tens and ones.
• Continue counting cubes and making groupings of tens and ones. Lead children to see the relationship of the number words to the groupings of tens and ones.
• Give each child a tens and ones mat and a sheet of paper to write on. Then give each child 32 cubes. Have them group the cubes by tens and ones on their mat. You may want to have children make trains of ten at this point.
• Ask: How many tens do you have? (3)
How many ones? (2)
• Say: Now let's write that number.
• Ask: What number did you write? (32)
How did you know that was the number?
Children should say that the 3 shows how many tens and the 2 shows how many ones.
• Repeat with other two-digit numbers until children have a good understanding of place value to 99.