1. Knowing More About Decimals

2. Compatible Numbers Compatible numbers are numbers that are easy to compute mentally. Change your numbers to compatible numbers that are close to the original numbers. For example, instead of multiplying 4.71 by 57.13, it’s easier to think about 5 x 60. When we estimate, we can say that the product of 4.71 and 57.13 is about 300.

3. 1. Add the “front” digits, numbers in front the decimal point. 2. Estimate the decimals. 3. Add the estimated decimal to the front-end sum. Front-End Estimation 2.35 7.89 + 3.53 Front-end: 2 + 7 + 3 = 12 Fro nt- end : 5 + 9 Estimate decimals:.35 is close to 0..89 is close to 1 +.53 is close to 1 0 + 1 + 1 = 2 12 + 2 = 14

4. 1. DO NOT line up the factors by the decimal. 2.Place the number with more digits on top. 3.Line up the other number underneath, at the right. 4.Multiply 5.Count the number of decimal places in each factor. 6.Use the total number of decimal places in your two factors to move the decimal in your product to the LEFT. To Multiply:

5. 14. 3 x.21 3 4 1 0 6 8 2 3 1 1 + 1 + 2 3..21 x 14.3 300

6. 1.Check if you have a decimal in the divisor. If so, move the decimal point in the divisor to the right behind the last digit. 2.Move the decimal in the dividend to the right the same amount of places as the divisor. 3.Line up the decimal in the quotient. 4.Divide Dividing Decimals

7. 0.32.5 2 03 25.2. 512.5 2 10 2 5 5 2 5 0. 8 24 1 2 4 1 2 0

8. P = Parenthesis ( ) E = Exponents 1 2 M = Multiply - from left to right D = Divide - from left to right A = Add S = Subtract Please Excuse My Dear Aunt Sally (10 + 6) + (4 x 6) 16 + 24 40

9. Class-work: More Decimal Practice worksheet Class-work: More Decimal Practice worksheet Homework: Textbook Extra Practice (p. 642, #14 – 38 all) Homework: Textbook Extra Practice (p. 642, #14 – 38 all) Hoop Shoot, Football Math Hoop Shoot, Football Math