Know the value of digits in numbers to 100

General

Students learn the value of digits in numbers to 100. They learn which tens and ones make up numbers to 100 and are able to determine the value of a given digit in a number.

Common core standard(s)

1.NBT.B.2

Relevance

Discuss with students that it is important to know how numbers to 100 are put together, so you can use them in calculations later.

Introduction

Name a number between 21 and 100 and ask students to write the number down. Then they show their number, so you can check their answers.

Development

Show the tens and ones on the interactive whiteboard. Explain that tens are a group of 10 and ones are the numbers from 1 to 9. Show the MAB-blocks on the interactive whiteboard and/or show them in your classroom as well. Using the blocks, repeat the explanation of tens and ones. Next show an example with 42 objects. Explain that there are 40 in boxes and 2 loose ones. Together there are 42 objects. Discuss what the value of the digits in the number are and ask students to complete the TO-chart. Next practice as a class and complete more TO-charts. Discuss this again, but without the supporting visual and see if students are still able to complete the TO-chart. Next there are a few exercises where students need to indicate what the value of a digit are. Erase the boxes, or drag them away to show the correct answer.

Check that students understand the composition of numbers to 100 by asking the following questions:
What are tens? How do you know?
What are ones? How do you know?
Write the place value of 8 in the number 85. What is the value of the other number?

Guided Practice

Students practice with determining value of a number with supporting visual material with two given options. Then they practice with visual support where they need to come up with the answer. Finally they must give the answer with an abstract number without visual support.

Closing

Discuss with students that it is important to know how numbers to 100 are put together and to know the value of the digits in the numbers so they can prepare themselves for calculations later. Check that students understand tens and ones. To practice this again, discuss the value of digits in numbers by way of an exercise. Students must circle the correct numbers. They need to match a digit to value in a given number.

Teaching Tip

Students who have difficulty with this can be supported by using the Tens-Ones charts to help visualize the place of digits in a number. They can also be supported by the use of manipulatives, like MAB-blocks.