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Grade 4 PPT_Math_Q1_Lesson 20.pptx

  1. MATHEMATICS 4 UNIT 1 LESSON 20 Estimating the Quotient of 3- to 4- Digit Dividends By 1- to 2- Digit Divisors Mrs. MAY P. SANTIANO
  2. Tell the value of the underlined digit and then round it.
  3. Do you love surprises? When do you give a surprise to your loved ones? How do you feel when you see in their faces that they like your surprise?
  4. Leomar wants to surprise his mother on her coming birthday next month. He wants to give her a bag worth ₱ 475 as a gift. If he plans to save ₱ 19 a day, about how many days will he need to save to be able to buy the gift?
  5. What kind of son is Leomar? Do you also give surprises to your parents? Why do you want to surprise them? Do you also save money? What are the given facts? What is asked in the problem? What operations are you going to use? Do we need the exact/actual answer in the problem ? What word/s suggest that we need only to estimate?
  6. Estimating is an educated guess. There are times when an estimate is needed and not the actual one. Solution to the problem. So, Leomar needs about 25 days to save to be able to buy the gift.
  7. There are times when compatible numbers Are used to estimate quotients. Example.
  8. Let us compare the actual answer to the estimated one How is estimation done in the solution we have in the problem? What was done first to the divisor and dividend? Then, what was cancelled in the rounded divisor and dividend? Then, what was done next? • Are the quotients the same or different? • How near or far is the estimated answer to the actual one? • What will you do if the estimated answer is too large or small compared to the actual one?
  9. There are times that the estimated answer is too large or small if we round both the divisor and the dividend to the highest place value. One way to make our estimated answer reasonable or close to the exact answer is by using compatible numbers.
  10. Study the solutions below Rounding Method Compatible Number Method Actual Answer
  11. Answer: He needs 70 baskets with 24 pieces each and one basket with 14 mangoes. If the compatible method is used, he needs about 80 baskets. If the rounding method is used, he needs about 100 baskets. Which of the two estimates is closer to the actual answer? About 80 baskets is the closer estimate to the actual answer
  12. A.In your notebook, estimate the following using the Rounding Method: 1] 573÷6= 2] 8501÷9= 3] 8645÷32= 4] 2926÷47= 5] 4108÷82=
  13. B. Estimate the following using the Compatible Number Method: 1] 36 200÷56= 2] 3 209÷18= 3] 4 567÷93= 4] 7 331÷34= 5] 9 536÷16=
  14. Estimate then, choose the most ppropriate answer.
  15. To estimate quotients, round the divisor to the highest place value and use compatible numbers for the dividend to divide. This will make your estimated quotients reasonable.
  16. 1. About how many 23s are there in 4323? 2. About how many 52s are there in 1322? 3. About how many dozens are there in 105 pieces? 4. About how many minutes are there in 3578 seconds? 5. About how many 26s are there in 5889? A. Estimate the answers to the following.
  17. 1. 1920 ÷ 6 < 300 or > 300? 2. 2040 ÷ 5 < 300 or > 300? 3. 3473 ÷ 5 < 400 or > 400? 4. 367 ÷ 7 < 50 or > 50? 5. 6575 ÷ 8 < 800 or > 800? B. Use estimation to tell whether the exact quotient is less than or greater than the given number.
  18. 1. Which is a better buy. 1 box of 6 pencils at ₱ 27 or 1 pencil at ₱ 5 each? Why? 2. If a kilogram of siniguelas costs ₱ 60, about how many kilograms can you buy with your ₱ 200? 3. Which would you buy, 1 kilogram of powdered detergent at ₱ 280 or 6 small packs of 54 grams of the same detergent at ₱ 94? Why? B. Answer the following problems
  19. Find the estimated quotient.
  20. Estimate the quotient by rounding method.