2. How to Divide, Multiply, Subtract and Add.Percentages And Decimals

3. %Percentages% First of all we are going to talk about Percentages A percentage is a part of a whole number or in other word a part of a fraction that is over 100. Percentage came form a Latin phrase per = centum ‘%’ is the shortened way of saying Percentage. Centum = out of a hundred

4. How To Convert Percentages Into Decimals A decimal is a part of number 1. To convert from percent to decimal, you must divide by 100 and remove the % sign. Example: 50% = 0.5 75% = 0.75 9% = 0.09 11% = 0.11 30% = 0.30 45% = 0.45 5% = 0.05 10% = 0.1 17% = 0.17 32% = 0.32 99% = 0.99 87% = 0.87 100% = 1

5. +Adding Percentages% Adding percentages is the same as adding whole numbers with whole numbers. Example: 20%+15%=35% Is the same way of saying (with out % sign) 20+15=35

6. -Subtracting Percentage% Subtracting percentages is the same as adding whole numbers with whole numbers. Example: 20%-15%=5% Is the same way of saying (with out % sign) 20-15=5

7. -Subtracting Percentage% Subtracting percentages is the same as adding whole numbers with whole numbers. Example: 0.20-0.15=0.5 Is the same way of saying (with out % sign) 20-15=5

8. ×Multiplying Percentage% Make the percentage to a fractions then multiply the fractions. Example: 20%×100=20/100×100=20

9. ÷Dividing Percentage% Make the percentage to a fractions then divide the fractions. 20%÷100=20/100÷100=20/10000=1/500

10. One Step Question World Problems (Part 1) Valen and Michael has Rp. 1.750.000 in their bank account. Michael owns 40% of the money in the bank account. Find the value of Michael’s part of the bank account?

11. One Step Model World Problems (Part 2) Michael Valen 40% 60% Rp. 1.750.000

12. One Step Solution World Problems (Part 3) Michael Valen 40% 60% 40% of the money belongs to Michael. 40/100×Rp. 1,750.000=Rp. 700.000 Michael has Rp. 700.000, Rp. 700.000 is 40% of Rp. 1,750.000

13. World Problems Two Step Question (Part 1) Matthew earned Rp. 100.000 on December. Matthew earned 25% more in the following month because he worked overtime. Find how much money increase is 25%?

14. Two Step Model World Problems (Part 2) December Rp. 100.000 January Rp. 100.000+25%

15. Two Step Solution World Problems (Part 3) The increase in Matthew’s earnings in the following month is, Rp. 100.000+25%=Rp. 150.000 Rp. 100.000 December Rp. 100.000+25% January Formula: 25%×100%=25%

16. Three Step Question World Problems (Part 1) My mom gave Kenneth and Darren an amount of M&Ms. Kenneth receives 70% of the amount and has 30 more M&Ms than Darren. How many M&Ms did they get altogether?

17. Three Step Model Word Problems (Part 2) 40% Darren 30% Kenneth 70%

18. Three Step Solution Word Problems (Part 3) 40% = 30 M&Ms 1% = ¾ M%Ms 100% = ¾ ×100=75 M&Ms 40% 30% 70% Kenneth and Darren got 75 M&Ms.

19. .Decimal. The word Decimal comes from a Latin word Decimus or Decimate which means ten. It was used to punish the tenth man of a group of soldiers that broke the rules. Decimals are numbers with a decimal point in the middle Example: 5.1, 8.2, 9.3, 6.4, 14.23 Decimals are based on the number 10. The digit left of the decimal is a whole number. The digit right of the decimal is a part of 1. Hundreds Thousands Ten s Tenths Ones Hundredths 2 8 8 8 2 2 .

20. +Adding Decimals. Adding Decimals is the same as adding whole numbers with whole numbers. Example: 0.20+0.15=0.35 Is the same way of saying (with out . sign) 20+15=35

21. -Subtracting Decimal. Subtracting Decimals is the same as subtracting whole numbers with whole numbers. Example: 0.20-0.15=0.5 Is the same way of saying (with out . sign) 20-15=5

22. ×Multiplying Decimals. Find the products as if they were whole numbers. Fix the digits behind the decimal point according to the total number of decimal places in the number Example: 3.21×1.1=3.531 The same meaning with 321×110=35310÷1000=3.531

23. ÷Dividing Decimals. Find the quotient as if they were whole numbers. Remember that you have the decimal point. Example: 0.25÷5=0.05

24. One Step Question World Problems (Part 1) Audrey has 12.5 test marks than Derien, If Derien has 70 marks how much is Audrey’s score. How many marks does Audrey have?

25. One Step Model World Problems (Part 2) 12.5 Derien 70 Marks Audrey 70 Marks+12.5 Marks

26. One Step Solution World Problems (Part 3) 70 Marks 12.5 Derien Audrey 70 Marks+12.5 Marks How many marks does Audrey have? 70 Marks+12.5 Marks=82.5 Marks Audrey has 82.5 marks

27. World Problems Two Step Question (Part 1) Paul has Rp. 20.250, Frank has Rp. 10.250 more than Paul. If Frank spent Rp. 19.500, how much money will he have?

28. Two Step Model World Problems (Part 2) Rp. 10.250 Rp. 10.250 Paul Rp. 20.250 Paul Rp. 20.250 Frank Frank Rp. 20.250+Rp. 10.250 Rp. 20.250+Rp. 10.250 2nd model Rp. 19.500

29. Two Step Solution World Problems (Part 3) Frank has Rp. 10.250 Rp. 10.250 Rp. 20.250+Rp. 10.250= Rp. 30.500 Rp. 20.250 Rp. 20.250 Paul Paul Frank Rp. 30.500 Rp. 20.250+Rp. 10.250 Frank Frank spent Rp. 19.500 then he has___ Rp. 30.500-Rp. 19.500= Rp. 11.000 Rp. 19.500

30. World Problems Three Step Question (Part 1) Tom has 3 pieces of wires. wire A is 9.67cm long, wire B is 148.74cm long, and wire C is 93.48cm long. Tom wants to cut three more wires. Wire D is twice as long of wires A and C, wire E is the average of the three wires and wire F is wire B-wire A. How long is wires D, E, and F going to be?

31. Three Step Model Word Problems (Part 2) Wire D + = ? × 2 =? 9.67cm 93.48cm Wire E + + = ? ÷ 3 =? 93.48cm 148.74cm 9.67cm Wire F - 148.74cm 9.67cm = ?

32. Three Step Solution Word Problems Wire D + = ? × 2 = 206.3 9.67cm 93.48cm Wire D is 206.3cm Wire E + + 93.48cm 148.74cm 9.67cm = ? ÷ 3 = 83. 9633333333 3333 Wire E is 83.96333333333333cm Wire F - 148.74cm 9.67cm = 139.07 Wire F is 139.07cm

33. Resources and Jobs Arnold : Make and arrange presentation, Make word problems. Jefferson Jo : fraction slides that is taken from Mrs. Deklay presentation. Kornelius : fraction slides that is taken from Mrs. Deklay presentation. Angela : decimal slides that is taken from Mrs. Deklay presentation. Erika : decimal slides that is taken from Mrs. Deklay presentation.

34. Thanks for Watching