Rounding Numbers (But Not To 10)

Objective

In this video, we'll investigate how to round to numbers other than multiples of ten. Sure, we could round 16 to the nearest ten, but what if we wanted to round 16 to the nearest 9? Or 12, 52, or 75? We take the routine math skill of rounding and force students to truly think about why a number rounds up or down.

Final answers: 62 rounds to 54, 32 rounds to 26, and 101 rounds to 96.

Steps

1. Round 15 to the nearest 9. Should it round up to 18 or down to 9?
2. Create a rule for rounding up to the next 9. Round three more numbers to the nearest 9.
3. Create a rule for rounding up to the next 7, 15, and 18.
4. See how to expand this rule to round to any number.

Resources

• Worksheet for Part 1 (PDF)
• Worksheet for Part 1 (Google Slides)
• Worksheet for Part 2 (PDF)
• Worksheet for Part 2 (Google Slides)
• Worksheet for Part 3 (PDF)
• Worksheet for Part 3 (Google Slides)
• Worksheet for Part 4 (PDF)
• Worksheet for Part 4 (Google Slides)