Numbers too big to compute
The question
Today is Monday. A comet will be overhead in 135 days' time.
What day of the week will that be?
Only the leftover moves the day
from:Monday· days:135
MoTuWeThFrSaSu
19×7=133
135−133=2
Monday+2=Wednesday
- Today is Monday, and the wait is 135 days.
- Days of the week come back round every 7, so a whole number of weeks later is the same day.
- So take the whole weeks out. 19 weeks is 19 × 7 = 133 days, and 135 − 133 = 2 days are left over.
- Now count 2 on from Monday — tomorrow is the first. That lands on Wednesday.
How it works.
- 01
Today is Monday, and the wait is 135 days.
- 02
Days of the week come back round every 7, so a whole number of weeks later is the same day.
- 03
So take the whole weeks out. 19 weeks is 19 × 7 = 133 days, and 135 − 133 = 2 days are left over.
- 04
Now count 2 on from Monday — tomorrow is the first. That lands on Wednesday.