Ms. Crusenberry 9-2013

Place Value

Name the Place Value of the Underlined Number 867.43 6.2395 148.372 9.3765

Answers Hundredths Tenths Thousandths Ten-thousandths

Comparing Ex: 19.368 __<___19.37 19.368 19.370 All numbers are the same until you get to 6 in the first set and 7 in the second set. The 7 is bigger; therefore 19.370 is the larger number.

Practice 3.6 _____ 3.486 17.228 _____ 17.28 0.023 _____ 0.00981 3.537 _____ 3.536

Answers > <

Multiple Numbers Which numeral is the largest? 5.332 5.359 5.317 5.332 5.359 5.317 14.04 14.198 14.2 9.308 9.3 9.299

Answers 5.332 5.359 5.317 14.04 14.198 14.2 9.308 9.3 9.299

Ordering Decimals You do this based on their place value. Ex: smallest to largest 3.06 3.219 3.058 answer: 3.058 3.06 3.219 Ex: largest to smallest 6.534 6.5 6.098 answer: 6.534 6.5 6.098

Practice – Smallest to Largest 12 11.98 12.006 6.08 6.8 6.76 4.368 4.3 4.319 72.008 72.01 72.0

Answers 11.98 12 12.006 6.08 6.76 6.8 4.3 4.319 4.368 72.0 72.008 72.01

Practice – Largest to Smallest 8 7.09 8.2 .903 .95 .921 7.9 7.902 7.829 11.361 11.35 11.3

Answers 8.2 8 7.09 .95 .921 .903 7.902 7.9 7.829 11.361 11.35 11.3

Rounding Decimals Rule – the number 5 or above to the right of the place value you are rounding to makes the number go up by one; 4 or less the number stays the same Ex. Round to the nearest tenth 4.569 = 4.600

Practice Round to the nearest tenths a) 2.34 b) 42.25 c) 14.6458 Round to the nearest hundredths d) 5.823 e) 2.124 f) .066 Round to the nearest thousandths g) 2.12394 h) 6.75689 i) .00057

Answers 2.30 42.30 14.6500 5.820 2.120 .070 2.12390 6.75690 .00060

Adding Decimals Rule – you must line up the decimals; fill in with zeros if needed Ex: 2.3 + 5 + .68 2.30 5.00 + 0.68 7.98

Practice 4.57 + 3.9 + 26 + 3.298 17 + .352 + 6.7 + 42.06 .663 + 48 + .43 + 37 5.058 + .7 + 9.006 + .49

Answers 37.768 66.112 86.093 15.254

Subtracting Decimals Rule – the same rule applies here that you did in adding decimals: line up the decimals and add zeroes if need be Ex: 12.5 – 4.2 12.5 - 4.2 8.3

Practice 15.6 – 2.34 5.8 – 2.14 5.2 - .423 14.6 - 12

Answers 13.26 3.66 4.777 2.6

Multiplying Decimals Rule – when multiplying decimals, count the number of decimal places in the problem to determine where to put the decimal point in the answer Ex: 2.31 x 4.2 2.31 two places x 4.2 one place 462 9240 9.702 three places

Practice 2.3 x 4.5 8.71 x 2.6 355 x 2.78 23.45 x 1.8

Answers 10.35 22.646 986.9 42.21

Diving by a whole number Dividing Decimals Diving by a whole number Rule – do not move the decimal inside the division house, bring it up into the answer. 5.3 Ex: 7 37.1 -35 21 -21 0

Continued Dividing by a decimal Rule – move the decimal outside the division house the amount of places you need to make a whole number Rule 2 – however many places you move the decimal outside of the division house, you must move it that many places on the inside of the division house

Example No. 1 12.6 .6 7.56 so 6 75.6 -6 15 -12 36 -36 0

Example No 2 **you will have to add a decimal and a 0 in order to move it inside the division house 4. .5 2 .5 2.0 5 20. -20 0

Practice 21.04 ÷ 8 37.38 ÷ 6 9.36 ÷ .6 13.95 ÷ .9 47 ÷ .8 315 ÷ .9

Answers 2.63 6.23 15.6 15.5 58.75 350

Renaming Fractions as Decimals Rule – Remember your decimal place value

Examples Rule - Place value is determined by the last number of the decimal; then reduce as needed .012 = 12/1000 = 3/250 .65 = 65/100 = 13/20 .7 = 7/10

Practice .82 .0198 .40 3.84 .19 .248

Answers .82 = 82/100 = 41/50 198/10,000 = 99/5000 40/100 = 4/10 = 2/5 3 84/100 = 3 21/25 19/100 248/1000 = 31/125

Renaming Fractions as Decimals Rule – Divide the numerator by the denominator .3 Ex. 3/10 10 3.0 -3 0 0

Practice 2/5 9/100 16/25 3/40 9/16 7/10

Answers .4 .09 .64 .075 .5625 .7

Repeating Decimals Ex. 3/11 .2727 **use rounding rules answer is .273 11 3.0000 - 2 2 80 -77 30 -22 80 -77

Practice **divide to four places, round to three places 19/22 2/33 5/6 4/9 10/11 2/3

Answers .864 .061 .833 .445 .909 .667