100 x 5 = 500
100 times 5 is 500. The shortcut for anything times 5 is to multiply by 10 and halve it: 100 x 10 is 1000, and half of 1000 is 500. The calculator takes any pair.
100 × 5 = 500
Adding 100 to itself 5 times gives the same answer.
Times ten, then halve
Five is half of ten, so any times-5 answer is the times-10 answer cut in half.
- 100 x 10 = 1000
- Half of 1000 = 500
Those two moves handle the pairs a times table never covers. 5 x 86 goes to 860, then to 430. 5 x 34 goes to 340, then to 170. Appending a zero and halving is faster than counting up in fives.
Watch the decimal point
100 x 5 = 500, but 100 x 0.5 = 50 and 100 x 50 = 5000. One digit, three answers, and the only thing separating them is where the point sits. Check the point before you doubt the arithmetic.
500 in the wild
- A hundred nickels is 500 cents, which is five dollars.
- Five days at 100 a day.
- Half of 1000, which is why 500 turns up so often as a round target.
Nearby answers
- 50 x 100 = 5000, ten times this answer.
- 100 x 2 = 200
- Every answer on the site