Decimal Place Value and Conversion of Measurement Units
This unit aims to extend understanding of decimal place value. They will be taught about the relationship between the value of digits in different places in a multi-digit number. They will learn to read and write decimals to the thousandths place and how to compare and round decimal numbers. In the second part of the unit they will use their understanding of place value to convert between different units within the same measurement system and use these conversions to solve multi-step problems. For example converting between mm-cm-m-km. Students will look at the units of measurement used for length, weight and capacity and begin to make connections between these systems.
Key questions
- What is the relationship between place value of whole numbers and decimals?
- How do we compare decimals?
- How can rounding numbers be helpful with estimation?
- How does the placement of a digit affect the value of a decimal number?
- What strategies will be helpful when converting between different units of measurement?
- When do I need to convert measurements?
- How can I use mathematical language with precision?
Place Value
In this unit, students will try to develop their understanding and their use of the language of place value.
What is this number?
3.33
Is it 3 point 33, or is it 3 and 33 hundredths? Which one does a better job of explaining the value of the threes in that number?
Students will explore what happens to a number when it is multiplied or divided by 10.
They will use base ten equipment to represent place value and explore how it can be used to represent tenths (0.1), hundredths (0.01) and thousandths (0.001).
Conversion of measurement units
When looking at converting from one unit of measurement to another, students will start with money.
Knowledge of the definitions of prefixes is important, for example:
Deci= tenth
Centi = hundredth
Milli= thousandth
Kilo= thousand
With an understanding of the relative value of millilitres and litres for example, students are equipped to solve problems such as How many 325ml soda cans are there in a 2l bottle of drink?
Next unit... 3D shape and volume.
