<span>It is easier to multiply. For example: 63 multiply by 7
</span><span>63 x 7 = (60+3) x 7 = 60 x 7 + 3 x 7 = 420 + 21 = 441
</span>
Another example : <span>25 x 73
</span>25 x 73 = (20+5) x (70+3) = 20 x 70 + 20x3 + 5x70 + 5x3
= 1400 + 60 + 350 + 15 = 1875
5x10^9
Just find out how many zeros there are
Answer:
I'm pretty sure the answer is a
The top left she should have added before multiplying
They are all even numbers and divisible by 2
