Comparing Decimal Lengths with a Ruler

This lesson teaches how to compare decimal lengths using a ruler. It begins with a review of place values, focusing on tenths and hundredths. The lesson explains how to use the centimeter side of a ruler, where each centimeter is divided into 10 millimeters. It demonstrates measuring objects and comparing lengths, such as 4.2 cm to 4.8 cm, and 2.01 cm to 0.99 cm. The lesson concludes with a summary of the comparison techniques learned.

What does the tenths place represent in a decimal number?

• The whole number divided into 2 pieces

• The whole number divided into 100 pieces

• The whole number divided into 10 pieces

• The whole number divided into 1000 pieces

How many millimeters are there in one centimeter?

• 5 millimeters

• 10 millimeters

• 15 millimeters

• 20 millimeters

When measuring with a ruler, where should you start?

• At the 1-centimeter mark

• At the middle of the ruler

• At the 0 mark

• At the end of the ruler

Which is longer: 4 and 2/10 centimeters or 4 and 8/10 centimeters?

• Cannot be determined

• They are the same length

• 4 and 8/10 centimeters

• 4 and 2/10 centimeters

In the example comparing 5 and 7/10 centimeters to 5 and 7/100 centimeters, which is greater?

• 5 and 7/10 centimeters

• 5 and 7/100 centimeters

• They are equal

• Cannot be determined