Rounding Up and Down
Students will be able to retell the rule for rounding to the nearest ten. Students will be able to decide to round a number up or down to the nearest ten.
- Begin the lesson by asking students to skip count by tens starting with bended knees and crouching low to the floor when they start at 0.
- Ask them to gradually stand up with each number. Use this as a demonstration of how numbers get bigger as we count forward. Explain that as we go up the numbers get higher.
- You can repeat the step in the opposite direction demonstrating that as we go down the numbers get smaller.
- Introduce the vocabulary at this time by explaining that rounding is a type of estimation that allows us to either round up to a big number or round down to a smaller number.
Explicit Instruction/Teacher modeling(25 minutes)
- Place the numbers 0 and 10 on the board and ask your students what numbers go between.
- Write all the numbers that go between 0 and 10 and describe that some numbers are closer to zero and some are closer to ten.
- Tell students that when rounding to the nearest ten, you use the digit in the ones place to tell you which way to go.
- Here, you will introduce the rhyme "1, 2, 3, 4 Hit the floor. 5, 6, 7, 8, 9 Now climb high!"
- Explain that "hit the floor" means to round down and "climb high" means to round up.
- Play Rounding to the Nearest Tens for further explanation.
- Guide students through the video, pausing for further explanation and questioning. For example, you may pause before the answer is given to ask students to repeat the rhyme and figure out if the number given will round up or down.
- Distribute hundreds charts that show how numbers can either round up or down.
Guided Practice(15 minutes)
- Ask your students to take out two crayons.
- Tell them to choose their round up color and their round down color.
- Give your students a number and tell them to find it on the chart.
- Then, ask them to decide if it will "hit the floor" or "climb high" then color it according to the color of choice. Make sure they don't mix up their colors.
- Repeat this process a few more times.
Independent working time(10 minutes)
- After the guided practice, you should now be able to write a few numbers on the board for students to color code on their own.
- Enrichment: For advanced students, allow them to round three digit numbers to the nearest ten.
- Support: Struggling students should underline the digit in the ones place to make it easier to identify and apply the rhyme.
- Assessment should be based on the color coding work the students did in the independent work time.
Review and closing(5 minutes)
- Play a quick body movement game. Call out a number from the rhyme.
- Tell your students to bend down and tap the floor if the number should be rounded down. If the number should round up, tell them to reach for the sky!