Type name and send: Y6 Level 5 Division with decimals January 2011 Next page

Decimals and Place Value A decimal is a number with a decimal point in it (6.52, 0.5, 0.01) The value of digits in a decimal is based on the number 10 The digits to the left of the decimal point represent whole number The numbers to the right of the decimal point represent some part of 1 Next Slide

The strange story of: 37.5  1.25 Dividing by a Decimal Number Next Slide

FIRST … QUICK ESTIMATE Come up with a QUICK ESTIMATE … 37.5  1.25 looks like it will be close to 37  1, which would equal just 37. SO… we will be looking for an answer around 37 and REJECT an answer of 300-something or 3-something. Next Slide

 37.5  To solve this problem using the “paper and pencil” procedure we would set it up like THIS. BUT… the regular division procedure does not work comfortably with decimal divisors… what can we do ? Next Slide

37.5  will give the same answer as 375  since we multiplied BOTH Dividend and Divisor by 10. …and we can do this multiplication by moving the decimal point one place to the right ! Next Slide

 and 375  will give the same answer as 3750  125 …since we multiplied BOTH Dividend and Divisor by 10 again. …and we can do this multiplication by moving the decimal point one more place to the right ! and annexing a zero in the ones place. Next Slide

and 3750  125 we can solve in the usual way Next Slide

Thousandths –2; thousands –1; hundreds –6; tens –4; ones –5; tenths –7; hundredths –8; thousandths Next Slide

Exercise Write the following numbers as decimals: Next Slide

Exercise Write the following numbers as decimals: Next Slide

Exercise Write the following number as a decimals: One hundred fifty-nine and twelve hundredths Next Slide

Changing Fractions to Decimals You can change a fraction to a decimal by dividing the numerator by the denominator Numerator; the top part of a fraction Denominator; the bottom part of a fraction –E.g. 4/5 = 4 ÷ 5 = 0.80 –5)4.00= 0.8 Next Slide

Now go on to the Website and do the XL exercise in Year 6 Next Slide

LO: To understand the effects of division by decimals I understand this idea fully. I have some understanding but I need more practice. I don’t understand this idea at all and need to work again on this unit of work. A B C Next page

LO: To convert fractions into decimals I understand this idea fully. I have some understanding but I need more practice. I don’t understand this idea at all and need to work again on this unit of work. A B C Next page

LO: To be able to divide a whole number by a number that is a decimal or which has decimals e.g. 60 ÷ 1.5 I understand this idea fully – I could do the sum above. I have some understanding but I need more practice. I don’t understand this idea at all and need to work again on this unit of work. A B C End of slide show.