Question

(4x10^4) x (2x10^3) in standard form

Answer 1

40,000 x 2,000
(4x10,000) x (2x1,000)
The answer is 80,000,000

Answer 2

Hey Ferne!
Multiplication is commutative and associative, so let's regroup these numbers so they're easier to multiply.

$\rm (4\times10^4)\times(2\times10^3)=(4\times2)\times(10^4\times10^3)$

Apply your exponent rule to the powers of 10, adding the exponents together, and multiply the 4 and 2,

$\rm =(8)\times(10^{4+3})$

We can drop the brackets as a final step,

$\rm =8\times10^7$

Hope that helps!