4 x 100 = 400
4 times 100 is 400. Multiplying by 100 puts two zeros after the 4. It is also the sum behind the 4 x 100 metre relay, where four runners cover 100 metres each.
4 × 100 = 400
Adding 4 to itself 100 times gives the same answer.
The working for 4 x 100
4 x 100 = 400. Multiplying by one hundred moves a number two places up, which for a whole number means writing two zeros after it. Read as repeated addition it is 100 plus 100 plus 100 plus 100.
400 is a square number
20 x 20 is 400, so its square root is exactly 20. That is not true of most answers on this site. It also means 400 halves cleanly twice over, to 200 and then 100.
Four hundred metres
The 4 x 100 relay is this multiplication run on a track. Four athletes cover 100 metres each and the total is 400 metres, which is one full lap of a standard outdoor track. The name of the event is the sum itself.
The zeros to keep an eye on
Two neighbours use the same 4 and land somewhere else entirely. 1000 x 4 is 4000, and so is 40 x 100. All three start from 4 and differ only in how many zeros follow it. Everything else is on the multiplication answers index.