L.O.2 To be able to use informal pencil and paper methods to support, record or explain divisions; to extend written methods to HTU÷U; to choose and use appropriate ways of calculating mental, mental with jottings, written methods.
. Q. A school has 392 chairs. How many tables can be equipped with 4 chairs each? Q. How could we work this out?
Our sum will be 392 ÷ 4 Q. Approximately how many tables can be equipped?
392 ÷ 4 We know that 90 x 4 = 360 and 100 x 4 = 400 so our answer will be between 90 and 100. Work in pairs to solve this problem on your whiteboards.
There should be 98 tables with four chairs around each! How did you do it?
You have a copy of Activity Sheet 3.1 You should choose an appropriate method for the calculations (mental, jottings or written) but not use calculators. Record your calculations on the sheet.
Q. Which shapes have left us with spare chairs? 392 is exactly divisible by 4, 8, and 7 – no spare chairs - but has a remainder when divided by 5, 6 and 9 – spares! Q. How do we know when a number is divisible by 2? Q. What does divisible mean? To be divisible by 2 the last digit must be AN EVEN NUMBER.
Q. How do we know when a number has 4 as a factor i.e. is divisible by 4? Which of these have 4 as a factor? 222 267 232 168 145783 124 444 312 516
These have 4 as a factor because the LAST 2 DIGITS are divisible by 4. 232 32 168 68 124 24 444 44 312 12 516 16
Q. How do we know when a number can be divided by 5 without a remainder i.e. has 5 as a factor? Write some numbers which do and some which do not have 5 as a factor. Use columns.
By the end of the lesson the children should be able to : Discuss, explain and compare methods; use multiples of the divisor; solve problems involving HTU ÷ U calculations