Answer: 240,000
Step-by-step explanation: Ok so to get the answer we first do
10 x 20 which is 200 then you do 200 x 30 which is 6,000 then we times the last number which is 40 which would look like 6,000 x 40 which equals 240,000. Hope this helps but also a quicker way in your head could be lining them up straight and down in your head with all the numbers and with all the zeros you will no the answer will have 4 zeros on the end of the answer then do 1 x 2 = 2 x 3 = 6 x 4=24 so then add the four zeros on the end and there you go you get your final answer of 240,000.