Lesson 2: Reviewing Rounding to 10 and 100


Activity 1: Rounding Practice

Materials: Interactive Notebook
For a quick review of rounding to 10 and 100, provide time for your child to watch the music video at the following web link.
Web Link
Tell your child to read the "Rounding Round-Up" sheet and then add it to her Interactive Notebook. Explain that this sheet summarizes rounding to 10 and 100 and also shows rounding to the thousands place (which will be covered later in this unit).

Next, provide time for your child to complete the short quiz at the following web link. Allow her to refer to the video or "Rounding Round-Up" sheet as needed.
Web Link
Student Activity Page

Activity 2: Rounding the Time

Materials: geared clock (kit)
Say, "In real life, we often round when we talk about time. For example, instead of saying I started doing something at 3:23, I'm more likely to say I started at 3:25 or 3:30." Give your child the geared clock, and ask her to show 5:17 on it. Ask, "What hour is this time closer to, 5 o'clock or 6 o'clock?" (5 o'clock) Say, "You just rounded the original time to the nearest hour."

If your child would benefit from a quick review of quarter times and time to five minutes, ask her to begin at an hour (for example, six o'clock) and move the minute hand around the clock to first show quarter hours and then to show five minute times.

Now, with the geared clock still showing 5:17, pose the following questions, and help your child find the answers as needed:
  • What is the time to the nearest quarter hour? (5:15)
  • What is the time to the nearest five minutes? (5:15)
Repeat this process with 9:42. Your child should find the following times:
  • Nearest hour: 10:00
  • Nearest quarter hour: 9:45
  • Nearest five minutes: 9:40
Your child will complete the "Rounding the Time" sheet by filling in the blanks provided. Encourage her to use the geared clock as she works, and remind her to read the instructions carefully.
"Rounding the Time" Answer Key
Student Activity Page