<span>Understand that:
• the sum of two positive numbers is greater than either
number.
Understand that addition is the inverse of subtraction (addition
reverses subtraction and vice versa) and use this to check
results.
Respond rapidly to oral or written questions, explaining the
strategy used. For example:
• 654 add 50… Add 68 to 74…
• 7 add 12 add 9… Add 15, 6, 4, 15 and 1…
• What is the sum/total of 26 and 39? And of 13, 62 and 3?
• How many altogether are 121 and 35? And 61, 37 and 6?
• Increase 48 by 22.
• Which three numbers could have a total of 103?
Are there any others?</span>
No, her answer is not reasonable because one yard is equal to 3 feet.
I like the substitution method. Which is when you make one equation equal only x or y and plug it into the other equation)
There is also the graphing method. If you graphed it, it might not be quite as accurate (at least on hand, on computer you would be pretty exact)
Then there is the elimination method. You multiply one of the equations by a coefficient so that you can eliminate x or y from the equation.
Add each term and divide it by 2.
5+7 = 12
12/2 = 6
-2 + 6 = 4
4/2 = 2, then add the i back on to get 2i.
The midpoint is 6 + 2i
Simple interest = Cost Price + (Interest Percentage of Cost Price × number of years or months we are paying off)
a) SI = £20 000 + (5% of £20 000 × 4)
SI = £20 000 + (£1000 × 4)
SI = £20 000 + £4000 = £24 000
b) SI = £20 000 + (5% of £20 000 × 3)
SI = £20 000 + (£1000 × 3)
SI = £20 000 + £3000 = £23 000
£24 000 - £23 000 = £1000 that you saved!
