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How to Set Up Your Do Now Notebook. Date Do Now # _______. IMPORTANT NOTE! Every Do Now entry must have the heading of the date and the do now number. Draw a line at the end of each Do Now entry. You will write the next day’s Do Now underneath it.
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How to Set Up Your Do Now Notebook Date Do Now # _______ • IMPORTANT NOTE! • Every Do Now entry must have the heading of the date and the do now number. • Draw a line at the end of each Do Now entry. You will write the next day’s Do Now underneath it. • DO NOT use a new page for each Do Now entry! • Use the back of notebook pages too! • If you do not follow these instructions and run out of paper, you must buy your own Do Now notebook!
Do Now # 1 – Thurs, 9/12 500 – 324 2) 38,000 – 5,356 3) Explain how you regrouped to subtract in the above problems.
Chapter 1 PreTest Dipstick Quiz & Materials Collection
Chapter 1 Lesson 1 Estimating with Whole Numbers
Why Estimate??? Sometimes in math you do not need an exact answer. Instead, you can use an estimate. Estimatesare close to the exact answer but are usually easier and faster to find.
How do we Estimate??? When estimating, you can round the numbers in the problem to compatible numbers. Compatible numbers are close to the numbers in the problem, and they can help you do math mentally.
How do we figure out which numbers are COMPATIBLE ? To find a compatible number when estimating you must ROUND to an indicated place value position…
How do we ROUND??? Remember this saying… 4 or below, leave it alone… 5 or above, give it a shove… You use this phrase when rounding, by looking ONLY at the number to the RIGHT of the indicated place value position. After you have decided to round up or down, you MUST change ALL the numbers to the right of the indicated place value position to ZEROS.
4 or below, leave it alone…5 or above, give it a shove… Steps 1) Underline the digit in the indicated place value position 2) Circle the number to the right of it 3) If the circled number to the right of the indicated place value position is… 4 or below leave the underlined digit alone 5 or above ROUND UP the underlined digit 4) Change all numbers to right of the place value position to zeros.
Let’s Practice Rounding Hundred thousands Round to the thousands place value hundreds tens Ten thousands 941,312
Let’s Practice Compatible Numbers (not given a place value to round to) NumberCompatible Number 98,312 2,713 541 953 48
Remember! • When rounding, look at the digit to the right of the place to which you are rounding. • If that digit is 5 or greater, round up. • If that digit is less than 5, leave the number alone. Remember use Rounding Rules 4 or below leave it alone… 5 or above give it a shove…
Example 1 Estimate the sum by rounding to the place value indicated. 12,345 + 62,167; ten thousands 1) Identify the digit in the indicated place value position 3) Round REMEMBER… 4 or below, leave it alone 5 or above, give it a shove 2) Look at the number to the RIGHT 4) Change ALL numbers to the right to Zeros. Where do we start?? 5) Add
Example 2 Estimate the sum by rounding to the place value indicated. 4,983 – 2,447; thousands
Example 3 Estimate the sum by rounding to the place value indicated. 4,983 – 2,447; hundreds
You Try… Estimate the sum by rounding to the place value indicated. 43, 312 + 131, 653; thousands
Over??? Under??? An estimate that is greater than the exact answer is an overestimate. An estimate that is less than the exact answer is an underestimate.
Word Problem 1 Chelsea is planning the annual softball banquet for the 8 teams in the region. Each team has 18 members. Estimate how many plates she will need to buy if all the members attend. How would we solve this if it wasn’t an estimation problem?
Chelsea is planning the annual softball banquet for the 8 teams in the region. Each team has 18 members. Estimate how many plates she will need to buy if all the members attend. Find the number of softball members. 8 18 8 20 = 160 players ESTIMATE: the number of players in each team How we find EXACT answer Chelsea would need about 160 plates. Is this an overestimate or underestimate?
Word Problem 2 Mrs. Blair will drive 103 miles to the airport at 55 mi/h. About how long will her trip take? What operation do we need to solve this? Can we find compatible numbers for each?
You Try…Word Problem Ms. Oliver wants to buy the entire seventh-grade new pencils. There are 5 seventh-grade homeroom classes of 28 students. Estimate how many pencils Ms. Oliver needs to buy for all of the students.
Independent Practice Text pg 4 #1-12