Mod 4 Unit 3
Decimals
A part or fraction of a whole number
Practice 3
Round to the nearest tenth. 1. 7.25 = 7.3 2. 245.39 3. 0.95 = 1.0 4. 3.825 = 5. 25.02 =25.0 or 25 6. 128.09 = 7. 0.0943 =0.1 8. 349.37 = 9. 9.89 =9.9 10. 0.087 =
Practice 7
Using the same method, arrange the sets of numbers from largest to smallest. 1. 0.25, 2.5, 2.025, 0.025 = 2.5, 2.025, 0.250, 0.025 2. 0.01, 1.01, 10.01, 1.001 = 3. 0.5, 5.15, 5.55, 5.05, 0.05 = 5.55, 5.15, 5.05, 0.5, 0.05 4. 0.04, 0.004, 0.4, 0.044 =
Practice 6
Which decimal number is larger? 1. 0.0895 or 0.89 =0.89 2. 0.497 or 4.97 = 3. 0.6 or 0.066 = 4.25 4. 100.75 or 100.07 = 5. 0.0679 or 0.675 = 0.675
Practice 5
Which decimal number is smaller? 1. 1.2 or 1.02 =1.02 2. 0.075 or 0.75 =0.75 3.4.25 or 4.2505 =4.25 4.0.4 or 0.04 = 0.4 5.0.0033 or 0.03 =0.0033
Comparing Decimals:
Which is larger: 0.081 or 0.28? STEP 1: Line the decimals up like buttons on a shirt. This will help make the decimal numbers appear to have the same number of decimal places. 0.0810 0.28 STEP 2: Add zeros to fill in the empty place values so that the decimals have the same number of places or digits. 0.081 0.280 STEP 3: Disregard the decimal point for a moment and read the numbers as they are written from left to right, including the added zero place value. 0.081→eight-one 0.280→two hundred eighty So, 0.28 is larger than 0.081.
Practice 1
Write the decimals in words. 1.0.14 = Fourteen hundredths 2.0.2= 3.0.08 = Eight hundredths 4.2.5 = 5.103.82= One hundred three and eighty-two hundredths 6.15.002 = 7.125.14 = One hundred twenty-five and fourteen hundredths 8.53.07 = 9.18.08= eighteen and eight hundredths 10.0.126 =
Practice 2
Write the following words in decimal numbers. 1.three tenths = 0.3 2.fourteen thousandths 3.six hundred and twelve thousandths = 600.012 4.twenty hundredths 5.eight and five hundredths = 8.05
Adding Decimals
A whole number always has a decimal point to the right side of the final number: 56=56. 2.32+0.14=?→2.32 +0.14 2.46 48+1.75= →48.00 +1.75 49.75 ←−−−−−−−−−−−−−−−−−−−−−−−−−−Place a decimal point and fill the empty spaces with zeros. Lining up the decimals is the first step in ensuring the correct answer for the addition of decimals. 2.46+0.005+13= -----→2.460 0.005 +1.300 =3.765 Fill the empty spaces with zeros. 2.46+0.005+13=→2.460+0.005+1.300= 3.765 STEP 1: Line up the decimals. The order of the numbers to be added is unimportant. STEP 2: Add the numbers and bring the decimal point straight down.
Round to nearest tenth
Round 4.97 to the nearest tenth. STEP 1: 4.9-7 STEP 2: 4.97 4.9 (Add 1 to 9)=5.0 or 5
Practice 4
Round to the nearest hundredth. 1.18.358 =18.36 2.0.899 = 3.4.290 =4.29 4.0.0650 = 5.0.0074 =0.01 6.$2104.556 = 7.35.708 =35.71 8.9.56741 = 9.46.085 =49.09 10.4.719