Decimal numbers. Tenths and hundredths. 2 Write the decimal number each arrow points to.

Transcription

1 Decimal numbers Tenths and hundredths A decimal point separates whole numbers from decimal fractions tens (30) 9 9 tenths ( 0 ) 8 ones (8) 6 6 hundredths (00 ) 9 6 = 3896 for the Middle East PBA + Maths aw_00 This is read as thirty-eight point nine six Copy and complete this chart Number Tens Units tenths hundredths Write the decimal number each arrow points to a b c d 0 0 f Maths for the Middle East PBAg aw_002 4 aw_ _textindb 4 h 2 Maths for the Middle keast PBA aw_003 e i j 2 3 l m 4 n o 48 4 /03/202 :38

2 3 Read the decimal numbers from question 2 Write each number in words 4 Write these as decimals c) e) 9 f ) 4 g) 38 2 h) Write these as decimals 9 tenths 3 tenths c) 4 hundredths 9 hundredths e) 8 tenths f ) hundredths g) 8 hundredths h) 6 hundredths 6 Write the value of the digit in each number Choose from 0, or 0 or c) e) 362 f ) 49 g) 8 h) 890 Try this Find pairs of numbers that have 8 as their halfway position 8 2 Can the pair of numbers be whole numbers? aw_ _textindb /03/202 :38

3 Thousandths Tens Ones 8 (0) (8) tenths hundredths thousandths ( ) ( ) ( ) We read 83 as eighteen point three one five The value of the digit is thousandths or This is a small fraction! Write each number in words Underline the word with the digit coloured red c) e) f )0 g) h) Write these fractions as decimals g) c) i) 9 32 j) h) e) 40 f) k) 3 2 l) Count in thousandths Write the next two numbers c) _textindb 6 /03/202 :38

4 4 This number line shows that 626 comes between 62 and 63 on a number line Draw number lines to show these decimals Maths for the Middle East PBA aw_ c) 2324 e) 6 f ) 229 Each of these digits is used to make different numbers Write these decimal numbers nineteen point three eight seven seventy-three point nine eight one c) thirty-one point seven eight nine seventeen and three hundred and eighty-nine thousandths e) thirty-eight and seven hundred and ninety-one thousandths Try this Rearrange each set of digits to make the number nearest to aw_008 c) aw_009 aw_00 aw_ _textindb /03/202 :38

5 Multiplying and dividing by 0 and 00 Follow these rules for multiplying and dividing numbers by 0 and 00 Multiplying by 0 Move the digits one place to the left = Multiplying by 00 Multiplying by 00 is the same as multiplying by 0 and then multiplying by 0 again 648 Move the digits two places to the left = 84 Dividing by 0 Move the digits one place to the right = Dividing by 00 Dividing by 00 is the same as dividing by 0 and then dividing by 0 again 0348 Move the digits two places to the right = 036 Answer these = = c) 6 0 = = e) 0 0 = f ) = g) = h) = i) = j) = k) = l) = 46 0 = 8 0 = c) 43 0 = 06 0 = e) 43 0 = f ) 82 0 = g) = h) = i) 00 = j) = k) 8 00 = l) = 2 Answer these _textindb 8 /03/202 :38

6 3 Copy and complete these Use 0, 00, 0 or c) 4382 e) 0006 g) f) h) these 4 Answer What number does 44 have to be multiplied by to get 44? aw_0a What number does have to be divided by to get 0? c) A number is multiplied by 0 to give 6 What is the number? What number divided by 00 gives 02? e) A number is divided by 00 to give 004 What is the number? f ) A number is multiplied by 00 to give 348 What is the number? g) What number multiplied by 00 gives 8? h) What number divided by 00 gives 0399? Try this The 6 in 236 is two columns away from the 6 in 236 It is 00 times greater The 8 in 368 is two columns away from the 8 in 368 It is 00 times smaller Answer these What would you multiply the 8 in 48 by, to give it the same value as the 8 in 48? What would you multiply the in 3 by, to give it the same value as the in 3? c) What would you divide the 6 in 46 by, to give it the same value as the 6 in 46? How many times greater is the in 2 than the in 2? e) How many times smaller is the 3 in 039 than the 3 in 039? _textindb 9 /03/202 :38

7 Comparing and ordering decimals When you put decimals in order, compare each digit, starting with the digits with the largest place value These are the digits on the left of the number Put these in order, starting with the smallest Compare the whole numbers, then the tenths, then the hundredths and finally the thousandths 908 < 984 < 984 < 98 Copy the number lines Join the black numbers to the correct position on the number lines aw_ each set of numbers in order Use the signs < or > 2 WriteMaths for the Middle East PBA aw_03 Start with the smallest number 4 < < c) Start with the largest number e) g) > > f) h) aw_03a _textindb 0 aw_03a /03/202 :38

8 3 Write each set of numbers in order Start with the smallest number each time c) aw_04 aw_0 aw_06 chartforshows theeast height the Middle PBA and weight of a group of men 4 This Maths aw_0 Mike Steve Andy Ian Tom John Height (m) Weight (kg) Write the heights in order, starting with the tallest Write the weights in order, starting with the heaviest Try this The masses of planets in the Solar System have been compared to the mass of Earth If we say that the mass of Earth is, then the masses of the planets are shown in the table Write these planets in order, starting with the greatest mass Planet Mass (compared with Earth) Planet Mass (compared with Earth) Uranus 436 Neptune 48 Saturn 96 Earth 000 aw_08 Venus aw_02 08 Jupiter aw_ aw_022 The mass of Earth is approximately 3 billion tonnes aw_020 aw_ _textindb /03/202 :38

9 Rounding decimals Rounding decimals makes them easier to work with For example, this bag weighs 632 kilograms kg This measurement is very exact Usually, you only need to know that it is about 6 kg, or if you want to Maths be a little more accurate that it weighs about 64 kg for the Middle East PBA Decimalsaw_024 are usually rounded to the nearest whole number or to the nearest tenth Rounding to the nearest whole number Look at the tenths digit If it is or more, round up to the next whole number If it is less than, the units digit stays the same 6 rounds up to 48 rounds down to Rounding to the nearest tenth Look at the hundredths digit If it is or more, round up to the next tenth If it is less than, the tenth digit stays the same 3 rounds up to rounds down to 46 Copy this number line Join each of these decimals to the nearest tenth on the number line Maths for the 20 Middle East PBA aw_02 2 Round each amount to the nearest whole unit 26 cm cm 92 l l c) $8349 $ 20 g g e) 08 km km f ) 46 kg kg _textindb 2 /03/202 :38

10 3 Round each amount to the nearest tenth of a unit $0 $ c) m e) km 364 l l m 9828 kg kg km f ) $4 $ 4 Round each of these to the nearest whole number c) e) 290 f ) 448 These calculator displays show amounts of money in dollars Write them correctly using $ Round them to the nearest cent if necessary c) e) f) ment AssessMaths for the Middle East PBA aw_026 These are the wingspans and weights of some of the largest owls in the world Owl Wingspan (cm) Weight (kg) Cape eagle owl 94 8 Eurasian eagle owl Great horned owl Pharaoh eagle owl Snowy owl c) Write the owls in order of wingspan, starting with the longest Write the owls in order of weight, starting with the lightest Round each wingspan to the nearest centimetre Round each weight to the nearest tenth of a kilogram _textindb 3 /03/202 :38