1.862 x x 10. The 'Estimation' Game. April 03, SB Multiplying and Dividing Decimals.notebook. MINDS ON (Elicit & Engage)

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1 rounding MINDS ON (Elicit & Engage) wake up Work with a shoulder partner to answer the following question. Be prepared to explain HOW you got to your answer, what strategies you used, and What operations you used and why. Record your answer in your math notebook. Mar 11 10:27 PM Mar 19 7:45 AM With the same partner, solve the problem below. Be prepared to explain HOW you got to your answer, what strategies you used, and What operations you used and why. Record your answer in your math notebook. ACTION! (Explore & Explain) The 'Estimation' Game We will have an 'around the world' style competition, whereby students will face off to estimate the answer to a multiplication or division question. The one with the closest answer will win a point for their team. Teams only have 15 seconds to answer. Jun 6 4:02 PM Mar 19 7:45 AM x x 5 Jun 7 1:40 PM Jun 7 1:48 PM 1

2 x x 6 Jun 7 1:48 PM Jun 7 1:49 PM x x 2 Jun 7 1:49 PM Jun 7 1:49 PM CONSOLIDATE & DEBRIEF (Elaborate, Evaluate, & Extend) In your notebook list at least 3 strategies you could use to estimate the solution to a multiplication or division question involving decimals. There Are 4 Ways to Estimate 1. Front End Rounding - keeping the first digit of the number the same and changing the rest to 0 Mar 19 7:45 AM Mar 11 8:59 PM 2

3 2. Compatible Rounding - using friendly or nice numbers that can be easily calculated mentally 3. Rounding - when you round the number up or down to the nearest whole, tenth, etc.. - anything below 5 is rounded down, 5 and above is rounded up Mar 11 9:05 PM Mar 11 9:25 PM 4. Compensation - As a class p.295 #8 Mar 11 9:28 PM Mar 11 10:13 PM With A Partner p. 295 # 10 Book Work pg's , 3,4, 5, 6,9, 11, 13 Mar 11 10:14 PM Mar 11 9:57 PM 3

4 Base Ten Blocks Jun 6 3:44 PM Mar 26 12:41 PM Tens Ones. Tenths Hundredths Represent 5.67 With Base Ten Blocks Mar 11 9:39 PM Mar 11 9:49 PM Mar 11 9:30 PM Mar 18 12:14 PM 4

5 Mrs. Green took out her whole family for lunch buffet at Pizza Delight. There are 7 people in Mrs. Green's Family including her. Each buffet costs $ Show your work with PNW. a. Estimate how much you think Mrs. Green will have to pay for her whole family. b. Calculate the cost of Mrs. Green's Bill for her family. Mar 18 12:27 PM Ms. Green will have to pay $ for her whole family of 7 to eat the buffet Pizza Delight. To get this answer I had to multiply $10.33 by 7 because for one person to eat the buffet it is $10.33, since she has 7 people in her family had to multiply the cost by the total number of people eating. First I drew my Place value chart with four places, the tens, ones, tenths, and finally the hundredths. The tens and the ones go before the decimal and the tenths and hundredths go after the decimal. When I began to multiply I knew to start with the hundredths place. So I multiplied 3 by 7 and got a product of 21, but I needed to regroup the two into the tenths place, I choose to represent that as 2 rods. Then I moved to the tenths place and multiplied 3 by 7 again and got product of 21. However, because I had to regroup the 2 as 2 rods I know that needed to add 2 to 21 to get a sum of 23. I then had to regroup the 2 into the ones place as 2 flats. Next I moved to the ones place and multiplied 0 by 7 and got a product of zero. However, because I had to regroup the 2 as 2 flats knew that I needed to add 2 to 0 to get a sum of 2. Due to the fact that my product only had a ones answer I knew that I did not need regroup any numbers. Next I moved to the tens place and multiplied 1 by 7 and got a product of 7. Once again I knew that I did not need to regroup any numbers Mar 24 10:17 AM p.302 2, 3, 4, 5, 6, 8, 10, 12 Mar 24 11:29 AM Mar 25 9:34 AM Mar 25 9:42 AM Mar 25 9:48 AM 5

6 pg , 2, 3, 5, 6, 7, 8, 9, 10, 11 DO THIS IF YOUR DONE Mar 26 9:09 AM Mar 26 10:42 AM Mar 27 10:24 AM Mar 28 9:08 AM Mar 28 9:29 AM Mar 28 9:33 AM 6

7 Apr 2 10:27 AM Apr 2 10:40 AM When I read the problem I found out they wanted us to find what the quotient was of $6.55 and 3. I know I must divide because I am sharing. To help divide I decided to draw a place value chart and represent my dividend using base ten blocks. I broke my place value chart into five columns: tens, ones, decimal, tenths, and hundredths. I then looked at my dividend ($6.55) and decided that I did not need to represent the tens place with 1000s cubes because there is only one digit in front of the decimal, so I knew that the 6 was in the ones place. I represented the ones place with 6 flats. I had a 5 in the tenths place, so I represented it with 5 rods. I also had 5 in the hundredths place, so I represented it with 5 unit cubes. I then drew a circle and split it into 3 equal groups because my divisor was 3. I know that division is opposite of multiplication, so I started from my highest place value in the divisor, which was the ones place. I then divided 6 by 3 and because I knew that 3x2 is 6 I knew the answer would be 2. I was able to put 2 flats in each section of my circle. I then placed the two in the tens place in my algorithm, I x 2 by 3 and placed the answer 6 under my 6 in the tenths place. I then subtracted 6 from 6 and got 0. I know that I cannot divide 0 by 3 so I had to bring down the five from the tenths place and was then able to divide 5 by 3 and my answer was 1 with 2 left over. Once again I knew that I could not dived 2 by 3, so I had to bring down my 5 from the hundredths place, by doing that I ended up with number 25, which means I then had to divide 25 by three and my answer was 8 with 1 one remainder. So after putting my decimal place two places in, my answer was $2.18 with a remainder of 1. Therefore each of my friends would get $2.18. Apr 2 11:08 AM There was 96.6 chips in bowl at a party, 7 people came to the party. All the chips were gone at the end of the party, how much did each person eat, if it was shared equally Apr 2 12:26 PM Apr 2 12:33 PM To find out what she did incorrectly I first estimated to see if her price was reasonable. So I rounded $6.97 up to 7 and multiplied it by 6 to get an answer of $42. I then compared it to the cashiers price of $418.20, her price was not reasonable, it was much too high. I then realized that she had the decimal is in the incorrect place and had extra 0 on the end. I discovered tha she accidently multiplied 6 by $69.70 to get $418.20, I know this because when I multiplied $6.97 (the price) by 6 (total number of cases) I got the answer of $ When I compared th price to my estimate I found it was reasonable. From this I decided that the cashier must have entered her numbers incorrectly in the cash registrar. She must have placed the decimal between the incorrect place values. Instead of putting it between the ones and tenths, she Apr 3 11:13 AM 7

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