Physics forces question query

A scale reads 0.4 mg
What is the force acting on the scale if the gravitational field strength is 9.8?

I calculated 3.92 * 10^-6 N
But apparently the anwer is 3.92 * 10^-3
I'm not sure if the answer is just wrong or I'm calculating it incorrectly

0.4 mg = 4 * 10^-7 kg
Mass in kg * gravitational field strength = force
Therefore
4 * 10^-6 * 9.8 = 3.92 * 10^-6 N

Take the mass in grams

Why does it need to be grams?

Take the mass in grams

You've converted wrong. 1MILI gram is one thousandth of a kilogram. I.e. 1mg = 1*10^3 kg hence 0.4mg = 0.4*10^-3kg.

how do you convert 0.4mg to kg? I'm confused by your working.

Actually 0.4mg isnt 4*10^-3 kg. Its 4*10^-3g. So therefore 0.4mg = 4*10^-6kg

A scale reads 0.4 mg
What is the force acting on the scale if the gravitational field strength is 9.8?

I calculated 3.92 * 10^-6 N
But apparently the anwer is 3.92 * 10^-3
I'm not sure if the answer is just wrong or I'm calculating it incorrectly

0.4 mg = 4 * 10^-7 kg
Mass in kg * gravitational field strength = force
Therefore
4 * 10^-6 * 9.8 = 3.92 * 10^-6 N

Actually 0.4mg isnt 4*10^-4 kg. Its 4*10^-4g. So therefore 0.4mg = 4*10^-7kg