ADDITION AND SUBTRACTION
JUMP STRATEGY
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JUMP STRATEGY GAMES:
SPLIT STRATEGY
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SPLIT STRATEGY GAMES:
COMPENSATION STRATEGY
Compensation is when one number is rounded to make the calculation easier. The other number is then adjusted.
Addition:
Addition:
Subtraction:
Watch some of these tutorial videos on how to compensate:
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COMPENSATION STRATEGY GAME:
PATTERN STRATEGY
When using the Pattern Strategy, you need to use your knowledge of patterns to solve problems easier.
For example: 5000 + 4000= ??
We know that 5 + 4 equals 9
So we could simply add the zeros at the end since we are only dealing with the thousands (all other place value places are 0)
Therefore, 5000 + 4000= 9000
Lets try: 500 – 200 = ?
We know that 5 – 2 = 3
So now we could just add the zeros since we are dealing with the hundreds place (all other place values are zero) 500 – 200 = 300
For example: 5000 + 4000= ??
We know that 5 + 4 equals 9
So we could simply add the zeros at the end since we are only dealing with the thousands (all other place value places are 0)
Therefore, 5000 + 4000= 9000
Lets try: 500 – 200 = ?
We know that 5 – 2 = 3
So now we could just add the zeros since we are dealing with the hundreds place (all other place values are zero) 500 – 200 = 300
BRIDGING DECADES
A decade is a period of 10.
Bridging Decades means counting by ones to the closest decade then counting by 10, 100 or 100.
Hint: When bridging decades ALWAYS look at the numbers on the ends first (numbers in the one's place value) and see if they are friends of 10.
For example: 34 + 26 = ?
If you look at the numbers in the ones place, you can see that they are 4 and 6 which add up to 10
So we can use bridging decades -
34 + 6 = 40
40 +20 = 60
See how we counted by ones to the closest decade then counted by tens? That's called bridging decades ! :)
How would you solve 673 + 7327 = ?
Take a look:
Bridging Decades means counting by ones to the closest decade then counting by 10, 100 or 100.
Hint: When bridging decades ALWAYS look at the numbers on the ends first (numbers in the one's place value) and see if they are friends of 10.
For example: 34 + 26 = ?
If you look at the numbers in the ones place, you can see that they are 4 and 6 which add up to 10
So we can use bridging decades -
34 + 6 = 40
40 +20 = 60
See how we counted by ones to the closest decade then counted by tens? That's called bridging decades ! :)
How would you solve 673 + 7327 = ?
Take a look:
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BRIDGING DECADES GAMES:
ORDER OF ADDENDS
Change the order of addends (numbers being added together) to form multiples of 10
E.g. 28 + 21 + 22 = ?
(28 + 22) + 21
= (50) + 21
= 71
Tip: Make sure you know your multiples of 10! If you look at the numbers in the ones place and find 2 numbers at the end (ones place) that add up 10 then ALWAYS add those two first. You would usually use order of addends when you have more than 2 addends (more than 2 numbers to add together- just like our question here!)
E.g. 28 + 21 + 22 = ?
(28 + 22) + 21
= (50) + 21
= 71
Tip: Make sure you know your multiples of 10! If you look at the numbers in the ones place and find 2 numbers at the end (ones place) that add up 10 then ALWAYS add those two first. You would usually use order of addends when you have more than 2 addends (more than 2 numbers to add together- just like our question here!)
PARTITIONING
PARTITIONING INTERACTIVE ACTIVITIES:
FORMAL ALGORITHM
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ALGORITHM GAMES:
INVERSE OPERATIONS WITH ADDITION AND SUBTRACTION
Inverse operations are useful because they reverse the effect of whatever operation you used and get you back to where you started.
The inverse operation of addition is subtraction.
The inverse operation of subtraction is addition.
For example, if we performed the addition 5 + 4 = 9, we could undo the addition by using the inverse, subtraction, 9 - 4 and get back to 5.
The inverse operation of addition is subtraction.
The inverse operation of subtraction is addition.
For example, if we performed the addition 5 + 4 = 9, we could undo the addition by using the inverse, subtraction, 9 - 4 and get back to 5.
INVERSE OPERATION GAME:
MONEY LESSONS
What do you use money to buy? In this clip we look at Australian money. See the different coins and notes that make up our money system. We investigate if size, (in coins) does matter. Check out how many 5 cent pieces you need to make two dollars. We also look at some currencies used around the world. Find out which country has the yen.
This is a colourful animation, with audio commentary, that describes how coins can be grouped together to represent different amounts of money. The resource uses examples of paying for everyday items using collections of coins, particularly when the cost of an item does not match the value of any one specific Australian coin. It explains and gives an example of how items can be paid for with more money than the cost of the item and then change returned as part of the transaction.
This is an activity about making choices to raise money for imaginary animals called gumbutangs. Their habitat is being eradicated and something must be done to save them. The user's first choice is between two websites, one a trusted one, the other a scam site. Then they are given choices about how to raise money for the gumbutangs and how to budget for, organise, publicise and price a fundraising event. These choices determine their pathway through the activity. Their final choice is how to spend the money they raised. The activity is intended for years 3 to 6 and takes about 30 minutes. Teacher and parent notes and a curriculum mapping are also available.
General addition and subtraction games
LANGUAGE/ TERMINOLOGY
Plus
Add Addition Minus The difference between Subtract, subtraction Equals Change (noun, in transactions of money). |
Is equal to
Is the same as Number sentence Empty number line Strategy Digit Estimate Round to |