Recognizing round numbers to 100 on bead strings

General

Students learn what bead strings are and can recognize round numbers to 100. Round numbers are the tens and fives.

Common core standard(s)

1.NBT.A.1

Relevance

Discuss with students that it is useful to recognize numbers on the bead string because they will be able to calculate faster. They don't need to count each bead to know which number is being indicated.

Introduction

Show the bead string on the interactive whiteboard or show a bead string to 100 to the class. Show and name the amounts. Ask the class if they are able to point out the right amount and repeat this exercise a few times. Next, show the students a number of written numbers and signs and ask which numbers are the same. Drag the numbers to the correct boxes.

Development

Explain what bead strings look like. Show that there are 100 beads on the string in groups of 10 red beads and 10 white beads. While using a bead string, show them to find out which number is being indicated by the question mark. You show that the question mark is further down the bead string and has passed a few groups of red and white beads. Count out loud using skip-counting by 10's until you read 50 beads. Next show that there are still 5 red beads before we reach the question mark. You count 5 more beads to 50, so 55 beads. Ask students if they can match the numbers given to the number being indicated by the question mark, and after that if they can give the number indicated by the question mark without any options given.

Check that students can recognize round numbers to 100 on bead strings by asking the following questions:
What does a bead string look like?
How do you know which number is being indicated by the question mark?
Are there as many red beads as white beads on the bead string?

Guided Practice

The students practice by first choosing an answer from four options. Next they practice giving the answer individually without any options to choose from.

Closing

Check that students know that a bead string is made up of multiple groups of red and white beads in groups of ten. Emphasize that it is useful to recognize numbers on a bead string to make calculation faster. Finally practice with bead strings by asking students to drag multiple numbers to their correct location on the bead string.

Teaching Tip

Students who have difficulty recognizing numbers on bead strings likely have difficulty with counting to 100. Have these students practice counting on the bead string counting the beads one by one. Next have them practice skip-counting by tens.