Parents Guide to Dividing by 10 & 100 This Power Point Presentation will Show Parents the Language We Use When Teaching Children How to Divide By 10 and 100 Organising numbers: We organise numbers in columns like this: H T Hundreds Tens U Units Only a single figure can go into each column. Organising numbers: After working with Thousands, Hundreds, Tens and Units the children are introduced to larger numbers HTh TTh Th H T U Hundreds of Thousands Tens of Thousands Thousands Hundreds Tens Units As always, only a single figure can go into each column. Organising numbers: We encourage the children to look at the numbers in groups of 3 digits. First look at the: HTU Then look at the : HTh TTh Th HTh TTh Th H T U Hundreds of Thousands Tens of Thousands Thousands Hundreds Tens Units Reading Big Numbers HTh TTh Th H T U Hundreds of Thousands Tens of Thousands Thousands Hundreds Tens Units 3 5 6 0 0 0 The 3 noughts in the HTU says ‘thousand’ Now read the HTh TTh and Th columns: 356 says ‘three hundred and fifty six’ this is the number of thousands. The complete number says: Three hundred and fifty six thousand. Reading Big Numbers HTh TTh Th H T U Hundreds of Thousands Tens of Thousands Thousands Hundreds Tens Units 1 3 7 0 0 0 Every time we see three zeros in the HTU columns we say ‘thousand.’ For the number above the number of thousands is one hundred and thirty seven. So the whole number reads: One hundred and thirty seven thousand. Reading Big Numbers M HTh TTh Th H T U Millions Hundreds of Thousands Tens of Thousands Thousands Hundreds Tens Units 1 0 0 0 0 0 0 After some practice with hundreds of thousands, the children are introduced to millions. We point out that to have a million we need one figure plus 6 zeros. To make the larger numbers we use a space to separate each group of 3 numbers. 1 000 000 one million 2 000 000 two million Dividing by 10 TTh Th H T U t h Tens of Thousands Thousands Hundreds Tens Units tenths hundredths To divide by ten we move the figures one place to the right to make the number smaller. The decimal point never moves. We read the colums like this: Hundreds Tens Units Decimal Point tenths hundredths Dividing by 10 TTh Th H T U t h Tens of Thousands Thousands Hundreds Tens Units tenths hundredths 3 2 We say:”There’s one zero in ten so we move one place.” 32 divided by 10 is: 3.2 TTh Th H T U t h Tens of Thousands Thousands Hundreds Tens Units tenths hundredths 3 2 Dividing by 10 4 3 2 H T U 4 3 2 t h 432 divided by 10 is 43.2 We have moved each digit one place to the right to divide by ten. We read the answer by saying, ‘forty three point two.’ Another Example H 6 1 T U 6 1 t h 61 divided by 10 is 6.1 We have moved each digit one place to the right to divide by ten. We read the answer by saying, ‘six point one.’ Finding 10% H 5 7 We use this same method to find 10%. 10% of 57 is 5.7 We read the number as five point seven T U 5 7 t h Dividing by 100 TTh Th H T U t h Tens of Thousands Thousands Hundreds Tens Units tenths hundredths To divide by hundred we move the figures two places to the right to make the number smaller. We say, “There are 2 noughts in one hundred so we move 2 places.” Dividing by 100 2 9 7 H T U 2 9 7 t h This time we move the figures 2 places to the right because there are 2 noughts in 100. We read the number as two point nine seven Multiplying by 10 2 9 7 0 Th H T U 2 9 7 t h This time we move the figures 1 place to the left because multiplying makes the number bigger. Notice that a zero needs to be added into the units column as the movement of the digits has left this column empty. Multiplying by 100 2 9 7 6 0 HTh TTh Th H T U t h 2 9 7 6 This time we move the figures 2 places to the left because there are two noughts in 100. Multiplying & Dividing by 10, 100 & 1000 M HTh TTh Th H T U t h th The same method is used for multiplying and dividing by 10, 100 & 1000. We use the amount of noughts in the number to remind us of how many spaces to move each digit. Multiplying / Dividing by: 10 Move 1 place 100 Move 2 places 1000 Move 3 places Remember : the decimal point never moves Click Below to Return to Our School Website. We hope this powerpoint will help you to work with your child at home. Please ask in school if you have any questions regarding our approach to teaching maths. http://www.killeanps.com