# How much is forty minus seven hundred?

Oct 14, 2016

$- 660$

#### Explanation:

When you subtract a bigger number from a smaller number, the remnant will always have a negative value.

One way of solving this is to find out the difference between them using the normal way of subtracting (smaller number from bigger number) and then adding the negative value.

So $40 - 700$ can be rewritten as $- \left(700 - 40\right)$

Now solve what is inside the brackets.

$- \left(700 - 40\right) = - \left(660\right)$

Removing the brackets we get $- 660$

Oct 16, 2016

There are several ways of doing this. For this question I chose an unconventional method. Takes longer to explain than do the maths.

$- 660$

#### Explanation:

Consider the example: write 6 as 2+4

I understand this to be called partitioning (splitting values)
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Using the above example approach:

Write$\text{ " 700" }$ as:

$660 + 40 \text{ which is the same as } 40 + 660$

So forty minus seven hundred is the same as

$40 - \left(40 + 660\right)$

Note that everything inside the bracket has to be multiplied by (-1)
$40 - 40 - 660$

But $40 - 40 = 0$ giving

$0 - 660 = - 660$
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Another format or approach or for this is:

$\textcolor{w h i t e}{} 40$
$\underline{40 + 660} \leftarrow \text{ subtract}$
$\textcolor{w h i t e}{4} 0 - 660$