Comparing and Ordering Decimals to Thousandths
About this lesson
Children hold decimal sticky notes and form a human number line, then order a second set with a partner on scrap paper. They practise comparing decimals to thousandths using place value. You need sticky notes, a marker and scrap paper. It takes about 15 minutes.
- Grade
- 5
- Subject
- Math
- Time
- 15 min
- Prep
- 5 min
Objective
Students will compare and order decimals to the thousandths place by comparing digits in each place value from left to right.
Prep
5 min: write 0.5, 0.45, 0.405, 0.054, 0.54, 0.504, 0.045 and 0.4 on eight large sticky notes
Materials
- sticky notes
- marker
- scrap paper
- whiteboard
Steps
- Give eight volunteers one sticky note each and have them stand at the front in a random line, holding their numbers so everyone can see.
- Ask the seated class to direct the volunteers into order from least to greatest, but before anyone moves, a student must explain why using place value, for example, 'Compare the tenths first.'
- When the line is finished, have each volunteer read their number as thousandths (0.5 is 500 thousandths, 0.45 is 450 thousandths) so the class can check and fix any mistakes.
- Write 2.3, 2.03, 2.303, 2.033 and 2.33 on the board and have pairs order them from least to greatest on scrap paper, adding one sentence explaining which pair was hardest to compare and why.
- Have two or three pairs share their order and reasoning, then run a quick second human number line with new volunteers if time allows.
Quick Check
Write 0.7, 0.07 and 0.707 on the board and have students hold up fingers showing which of the three numbers (1st, 2nd or 3rd) is greatest, then call on one student to explain.
Differentiation
Make it easier: Use decimals to tenths and hundredths only, and let students add zeros so every number has the same number of digits before comparing.
Make it harder: Ask pairs to write a decimal that fits between two neighbouring numbers in the line, such as one between 0.45 and 0.5.
Good For
- Review
- Before lunch
- Supply teacher
- End of day
