Rounding by Christina Hu

Practical Use

huc311 — 2018-10-09 04:12:39 UTC

In everyday use, when you are guesstimating how much you are going to pay for something at the store, or when you are estimating how much time it is going to take to do your homework.

Activity

huc311 — 2018-10-09 04:12:44 UTC

Estimate how many candies are in each jar.

Each team will need
--- Mason jar full of candy (Whoppers, Jelly beans, Candy Corn, Peanut M&M's, ect.)
--- Empty mason jar
--- Dixie cups
--- Tablespoon
--- Pencil
--- Paper

1. Measure out one tablespoon of candy.
2. Count the number of candies in that Tablespoon.
3. Round that number to the nearest 10. (Write this number down)
4. Dump that candy into the empty mason jar.
5. Count the number of Tablespoons of candy it takes to fill the jar about 1/4 of the way full. ( Keep tally marks)
6. Multiply the number of Tablespoons it took to fill the jar about 1/4 of the way full times the rounded number of candies.
7. Take the number from step six and multiply it by four. (This is your first estimate for the number of candies in the jar)
8. Next you will count out the actual number of candies.
9. Put 10 candies in each Dixie cup, this is simply to keep track of the candies and to make it easier to count so that you can get an exact number.

Round to the nearest 10.
Round to the nearest 100.

AZ Standard

huc311 — 2018-10-11 04:18:27 UTC

4.NBT.A
Generalize place value understanding for multi-digit whole numbers.

| 4.NBT.A.3 |
Use place value understanding to round multi-digit whole numbers to any place.

Refrences

huc311 — 2018-10-11 04:27:28 UTC

K-12 Standards Section. https://www.azed.gov/standards-practices/k-12standards/mathematics-standards/.
Pierce, Rod. (28 Jul 2017). "Estimation (Introduction)". Math Is Fun. Retrieved from http://www.mathsisfun.com/numbers/estimation.html.
Rounding and Estimating Activities. Retrieved from http://www.jumpstart.com/parents/activities/rounding-and-estimation-activities.
Redgrave, Juushika. 17 Oct 2011. Candy corn in a jar. https://www.flickr.com/photos/juushika/6256802810.
30 Sept 2018. Rounding. Retrieved from https://en.wikipedia.org/wiki/Rounding.
June 2018. Rounding and Estimating (Understanding why numbers are rounded). Retrieved from http://www.bbc.co.uk/skillswise/factsheet/ma06roun-e3-f-more-practical-examples-of-why-we-round-numbers.
https://www.amazon.com/NALAKUVARA-Wooden-Farmhouse-Ticking-Decorative/dp/B01C2G1LLG.
Pierce, Rod. "Rounding Numbers" Math Is Fun. Ed. Rod Pierce. 13 May 2017. Retrieved from http://www.mathsisfun.com/rounding-numbers.html.
2 April 2018. Mesopotamia. Retrieved from http://www.livius.org/articles/place/mesopotamia/.
Place Values. Retrieved from http://www.aaamath.com/plc21bx2.htm.
Rounding to the nearest 10, 100, 100. Retrieved from http://wtmaths.com/rounding_10_100_1000.html.
14 Nov 2015. Rounding Numbers: How hard can it be? Retrieved from http://www.usefuljs.net/2015/11/14/rounding-numbers-how-hard-can-it-be/

What is rounding?

huc311 — 2018-10-11 04:35:08 UTC

Rounding means making a number simpler but keeping its value close to what it was.

How to round

huc311 — 2018-10-11 04:35:21 UTC

If the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up. Example: 38 rounded to the nearest ten is 40¹
If the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down. Example: 33 rounded to the nearest ten is 30

Why rounding is important

huc311 — 2018-10-11 04:36:00 UTC

History

huc311 — 2018-10-11 14:44:57 UTC

The concept of rounding is very old, perhaps older even than the concept of division. Some ancient clay tablets found in Mesopotamia contain tables with rounded values of reciprocals.

Place Value Review

huc311 — 2018-10-11 14:51:28 UTC

  7 8 4
  | | |___{ones' place}
  | |__________{tens' place}
  |_________________{hundreds' place}

huc311 — 2018-10-11 15:12:06 UTC

Future Impact

huc311 — 2018-10-14 23:08:41 UTC

This activity is setting you up for future math classes, it is getting you ready for statistics and estimating populations.