Morning P6/7 🙂

Today we are going to focus practising the method of rounding and adjusting to solve addition and subtraction calculations.

Starter:

Watch the video and read the section below the video, which explains how to round a number:

https://www.bbc.co.uk/bitesize/topics/zh8dmp3/articles/zpx2qty 

Then, watch this second video and read the explanation below it on how to round decimal numbers:

https://www.bbc.co.uk/bitesize/topics/zh8dmp3/articles/zsvt97h 

Activity:

I can round and adjust the numbers to make it easier to solve mentally.

Remember, round the trickier number to the nearest 10, solve your calculation and don’t forget to either add on, or take away the extra part you did at the start to make the easier number.

Eg. a) 59 is the trickier number so I added 1 to round it to 60, which is an easier number to work with. I then solved the calculation and at the end adjusted it back, as I added an extra 1, I had to remember to take the 1 away.

Calculation	Rounded calculation and answer	Adjusted	Final answer
Eg. a)   59 + 45	(+1)60 + 45 = 105	105 – 1	104
b)   117 + 66	(+ _)    + 66 =
c)   89 + 55
d)   37 + 18
Eg. e)    92 – 49	92 – 50  (+1) = 42	42 -1 =41	41
f)   66 – 39
g)   104 – 27
h)   52 – 26

 

Challenge:

I can apply rounding and adjusting method to solve a word calculation.

• Firstly, decide is it asking you to add or subtract.
• Secondly, choose the trickier number and round it.
• Thirdly, solve it and adjust.

1. Jessica grew 674 watermelons and 122 cantaloupes. Mary grew 537 watermelons. How many watermelons did they grow in total?
2. Nancy had £651 in her bank. She spent £398. How much money does she have now?
3. Chloe had 95 Pokémon cards, and 7 were torn. Phil bought 36 of Chloe’s Pokémon cards. How many Pokémon cards does Chloe have now?
4. Miss Smith ordered some pizzas for a party, she order 57 pepperoni and 36 Hawaiian. How many pizzas did she order

There is also an activity up on Sumdog to continue practising your multiplication and division.

Finisher:

Create a couple of Qs for someone at home or a friend over the phone.

Ask them to round a given number to the nearest 10, 100 and 1000.

Create a couple of addition and subtractions Qs if you can too.