How do you evaluate $20 (\frac{1}{2} \times 35)$ $20(1/2 times35)$ ?

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Answer 1 · 2016-07-03T08:15:58

$350$ $350$

Notice that the brackets are not necessary because the only operation is multiplication.

Dividing (cancelling) first is a GREAT idea, because it makes the numbers smaller.

$20 \times \frac{1}{2} \times 35$ $20 xx 1/2 xx 35 " "$ gives $cancel20^10 xx 1/cancel2 xx 35$

which is very convenient because multiplication by 10 is a breeze.

This can be seen to give 350.

This type of calculation can be done by inspection rather than having to write it out.

How do you evaluate 20(1/2 times35)20(12×35)20(1/2 times35)?