Hours, minutes and the calendar · Usually met around P2
Counting days on a calendar
Both ends count: last − first + 1.
How to do it
Method
Both ends count: last − first + 1
5th to 12th: 12 − 5 + 1 = 8 days
Another way
Count them
5, 6, 7, 8, 9, 10, 11, 12 → 8
In full
When the first and last days both count, the number of days = last − first + 1: the 5th to the 12th is 12 − 5 + 1 = 8 days. Just subtracting misses the first day. Knowing the first day and how many, the last = first + days − 1; knowing the last and how many, the first = last − days + 1. Each row of a calendar is a week, every date in a column is the same day of the week, and each row down is 7 more. Or count the days one by one on the calendar to check.
Worked examples
Have a go first, then open each one for the answer and the working.
Example 1
What day of the week is the 9th of this month?
- A. Friday
- B. Thursday
- C. Sunday
- D. Wednesday
Choose the right answer
Show the answer and working
Answer: B. Thursday
Find the 9th and read the day at the top of its column: Thursday.
Example 2
An event starts on the circled 3rd and lasts 10 days, both ends counted. On what date is the last day?
Show the answer and working
Answer: 12
The first day is day 1: 3 + 10 − 1 = 12.
Example 3
The 2nd of this month is circled. What date is one week (7 days) later?
Show the answer and working
Answer: 9
One row down in the same column is a week later: 2 + 7 = 9.
Practise it in the game →Hours, minutes and the calendar · Free to start, unlimited questions, no download