Help students use two strategies that will help them figure out which three-digit number is greater than, less than, or equal to another three-digit number. Use on its own or with Let's Compare! Place Value Disks & Three-Digit Numbers.
Students will be able to compare two three-digit numbers based on meanings of the hundreds, tens, and ones digits, using symbols to record the results.
Language
Students will be able to compare the values of two three-digit numbers with academic vocabulary and more complex sentences using sentence frames and partnerships for support.
Introduction
(4 minutes)
Gather the students together and write the numbers 6 and 134 on the whiteboard.
Provide each student with a personal whiteboard and whiteboard marker.
Ask students to write down the number that is greater than the other number.
Give students a few moments and ask them to show you their whiteboards.
Encourage a few students to share out the strategy they used for figuring out which number was greater than the other number. Provide a sentence frame to support students in sharing their ideas (e.g. "I know ________ is greater than ________ because ________"). Elaborate that the number 6 only has one digit while the number 134 has three digits. This means 6 is equal to 6 ones, whereas 134 is equal to 4 ones, 3 tens, and 1 hundred. 134 is greater than 6 because it has values in the tens and hundreds place.
Keep 134 on the whiteboard and erase the number 6. Replace it with the number 234.
Repeat the process above and instruct students to write down the number that is greater than the other number on their whiteboard.
Allow a few students to share out their ideas, encouraging them to refer to the sentence frame for support.
Explain to the students that comparing two numbers with the same number of digits can be tricky. Create a place value chart on the whiteboard by drawing three columns and writing H, T, O in each column from left to right. Record both three-digit numbers in the place value chart.
Show students how to compare each digit, starting in the ones place. Circle the digits that are the same (4 ones, 3 tens). Elaborate that these digits are worth the same values and sketch a picture of base-ten blocks to help students visualize (small squares for ones, long rectangles for tens, big squares for hundreds). When you get to the hundreds place, put a star next to the 2 because that number is greater than the 1. Say, "This number has 2 hundreds and this number only has 1 hundred. I know that 234 is greater than 134 because 2 hundreds is more than 1 hundred." Sketch the hundreds using base-ten blocks for students to see.
Tell the class today they will compare and contrast two strategies they can use to figure out which three-digit number is greater than, less than, or equal to another three-digit number.