Strategies

Grade 3
> //**Use place value understanding and properties of operations to perform multi-digit arithmetic**// >> //__**Use place value understanding to round whole numbers to the nearest 10 or 100.**__// Estimating (Rounding) Strategies
 * Number & Operations in Base Ten**


 * **1.) The Number Line Strategy - paper version**


 * The Teaching Progression**

1. Hand out the "I Can" Checklist

2. Count by 100s from 0 to 1000 > //a. Check "I can" checklist//

3. Write the number to be estimated (e.g. 329) next to the problem number

4. Draw a Number Line <--> > //a. Check "I can" checklist//

5. Write the 2 hundreds that bracket the number to be estimated (e.g. 300 and 400) > //a. Check "I can" checklist//

6. Write the midpoint number (e.g 450) on the number line > //a. Check "I can" checklist//

7. Estimate the point on the number line where the number to be estimated should go > //a. Check "I can" checklist//

6. Draw an arrow to the nearest hundred (e.g. 300) > //a. Check "I can" checklist//

7. Write the number to be estimated to the nearest hundred (e.g. 329 =>300) > //a. Check "I can" checklist//


 * "I Can" Estimate to the Nearest Hundred Checklist**

□ I can or □ I can’t count by 100s

□ I can or □ I can’t draw a number line

□ I can or □ I can’t write the two 100s, my number is in between

□ I can or □ I can’t locate and label the midpoint between the two hundreds on the number line

□ I can or □ I can’t locate and label the approximate place on the number line where my number belongs

□ I can or □ I can’t draw an arrow from my number on the number line to the nearest hundred

□ I can or □ I can’t decide which hundred to round my number to


 * 2.) The Number Line Strategy - virtual manipulative** || ** Content Knowledge** * Count by 100s {0, 100, 200, 300, 400, 500, 600...}* [|CCSS.Math.Content.2.NBT.A.1 -]Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones.
 * Draw a number line
 * Decide which two hundreds the number is in between and place them on the number line
 * 463 is between 400 and 500
 * Locate the one's place
 * Locate the ten's place
 * Locate the hundred's place
 * Locate and Label the midpoint between the two hundreds
 * 450
 * Locate, estimate and label the number to be rounded on the number line
 * [|CCSS.Math.Content.2.NBT.A.4 -]Compare two three-digit numbers based on meanings of the hundreds, tens, and ones digits, using >, =, and < symbols to record the results of comparisons
 * Analyze the location of the number and decide which hundred that number is closest to

Technological Pedagogical Content Knowledge
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