Why is March 14 Pi Day? Numbers and dates in English

Q: How do you say numbers in English?

Learn zero to twelve, then build the rest : the teens end in -teen ( thirteen , nineteen ), the tens end in -ty ( thirty , ninety ), and a ten and a digit make twenty-one or sixty-five . Say 100 as one hundred . The A1 lesson Why is March 14 Pi Day? on edio.ai lays out 0 to 100 in a single table, then puts the numbers to work counting pies.

Q: How do you write dates in English?

In American English, the month comes before the day : March 14 , or 3/14 in numbers, and July 4 is 7/4 . Read short dates in that order too, so 6/5 is June 5, not May 6. Each month has its number, from January (1) to December (12), which makes 10/31 October 31.

Q: How do you write the numbers from 1 to 100 in words?

Numbers up to twenty and the tens are single words, and the others take a hyphen between the ten and the digit: twenty-three , thirty-four , fifty-six . Watch the spelling of a few: three gives thirteen and thirty , five gives fifteen and fifty , never fiveteen or fivety . And 100 is one hundred , two words with no hyphen.

Q: How do you say dates in English?

Say the month, then the day as an ordinal : March fourteenth , July fourth , December twenty-fifth , even when the date is written March 14 . A short date in numbers can also be read just as it looks, so 3/14 becomes three fourteen . Either way, the month always comes first in American English.

Q: How do you say decimals like 3.14 in English?

Say point for the dot, then each digit separately : 3.14 is three point one four , and 2.5 is two point five . That makes the 14 after the point one four , not fourteen , and the dot is never read as comma . Pi continues the same way, three point one four one five nine… , and its digits go on forever.

Q: Is it "forty" or "fourty"?

The right spelling is forty , with no u , even though four and fourteen both have one. Every number built on it follows: forty-one , forty-six , forty-nine . An easy way to remember it: fourteen is simply four plus -teen , but 40 drops the u.

Q: What's the difference between thirteen and thirty?

Besides the ending, the stress falls on a different part : thirTEEN is loud at the end, THIRty at the start. The same goes for 14 and 40, 15 and 50, through 19 and 90. When a listener isn't sure, say the digits: Fifteen or fifty? Fifteen! One, five. That exchange comes from the dialogue about a pie list in Why is March 14 Pi Day? , an A1 lesson on edio.ai.

Q: Why is Pi Day on March 14?

Because the US writes March 14 as 3/14 , and 3.14 is the start of pi, the number for circles. The idea works only with the month first: written 14/3 , the date would lose the link. Pi and pie sound the same, so people eat pie on the day, and the first Pi Day was held in 1988 at the Exploratorium, a science museum in San Francisco.

Q: How do I teach numbers and dates to beginners?

Let learners meet numbers in context before the rules , then have them choose, write and finally say them. Why is March 14 Pi Day? on edio.ai puts a poster with a $3.14 slice and a dialogue that adds up a pie order before its scheme, which covers the table to 100, the stress in 13 and 30 and month-first dates. A chat about the date and a box game end the practice.

Q: What's a good game for practicing numbers?

A box game where each box hides a number task : a student opens one, does the task aloud, and the class checks. In Why is March 14 Pi Day? on edio.ai, the boxes ask students to count in tens to a hundred, read 7/4 and 12/25 , spell F-O-R-T-Y for classmates to name, or say 13, 30, 14 and 40 while the others write down what they hear.

This A1 ESL lesson plan teaches numbers and dates in English through Pi Day on March 14.

Grammar: Numbers from 0 to 100 (forty with no u, a hyphen in twenty-one), the stress in 13 and 30, decimals read with point, and US dates, month first: 3/14.
Topic: Pi Day in the US, the day for pi and pie, at a pie shop in Brooklyn, New York, with words like slice, circle, math and calendar.
Activities: Students read a Pi Day poster, hear a dialogue and a radio host, practice in self-checking drills, chat about the date, open boxes of number tasks and record numbers at home.

What's inside

Chapter 1Pies and numbers!
- PictureUnlock
- Spin the wheel and answerSpin the wheelUnlock
- Study the wordsVocabularyTry it
- Look at the pictures and chooseChoose by pictureUnlock
Chapter 2Let's read: Happy Pi Day!
- Look at the photo: Pi DayPictureUnlock
- Read the posterReal-life documentTry it
- Read and mark true or falseTrue or falseUnlock
- Read again and choose the right answerQuizUnlock
Chapter 3Let's listen: how many pies?
- Listen to Priya and SamListeningTry it
- Transcript, for the teacherUnlock
- Listen again and choose the right answerQuizUnlock
- Listen to the radioListeningUnlock
- Transcript, for the teacherUnlock
- Listen and mark true or falseTrue or falseUnlock
Chapter 4Grammar: numbers and dates
- Study the scheme: numbers and datesGrammar schemeTry it
- Choose the right wordChoose the optionUnlock
- Write the numbers in wordsFill in the gapsTry it
- Choose the right answer: dates and numbersQuizUnlock
- Drag the words into the gapsDrag and dropUnlock
Chapter 5Let's talk: what's the date?
- Choose the right repliesChatTry it
- Open a box and answerOpen the boxUnlock
Chapter 6Homework
- Fill in the table: write the datesFill in the tableUnlock
- Unscramble the wordsAnagramUnlock
- Record yourself: numbers and datesSpeaking, checked by the teacherUnlock

Vocabulary

10 words and phrases from the lesson, each with a picture and audio in edio.

+7 more with pictures and audio in the lessonMore words

oven
math
calendar
party
birthday
count
write

Grammar: numbers 0 to 100, decimals and US dates

Pi Day is a number and a date at once: pi is about 3.14, and in the US, March 14 is written 3/14. That makes the day a natural way into numbers for beginners. Learners count Sam's pies, learn numbers in English from 0 to 100, read 3.14 aloud with point, and write every date with the month first.

Numbers 0–100, 3.14 and dates

Say and write numbers, say 3.14, and write dates the American way.

Numbers 0 to 100: fourteen, but forty

The table runs from zero to one hundred and marks the spelling trap: four and fourteen, but forty with no u. For the numbers between the tens, a hyphen joins the two words: twenty-one, forty-five, ninety-nine.

Numbers 0–100

0–9	10–19	20, 30 … 100
0 zero	10 ten	20 twenty
1 one	11 eleven	30 thirty
2 two	12 twelve	40 forty (no u!)
3 three	13 thirteen	50 fifty
4 four	14 fourteen	60 sixty
5 five	15 fifteen	70 seventy
6 six	16 sixteen	80 eighty
7 seven	17 seventeen	90 ninety
8 eight	18 eighteen	100 one hundred
9 nine	19 nineteen

Tens + one to nine: use a hyphen (-)

twenty, thirty … ninetyone, two … nine

twenty-one = 21

forty-five = 45

ninety-nine = 99

Thirteen or thirty? Listen for the stress

The teens are loud at the end, thirTEEN, and the tens at the start, THIRty. The stress is what tells 13 from 30, which is why Priya stops to check Sam's list: Fifteen or fifty?

13, 14 … 19: loud at the end

13 thirTEEN
14 fourTEEN
15 fifTEEN

20, 30 … 90: loud at the start

30 THIRty
40 FORty
50 FIFty

3.14: say point, then one digit at a time

A decimal is read with point, never comma, and the digits after it come one by one: three point one four, two point five. The digits of pi, 3.14159…, never end.

3.14 = three point one fourAfter the point, say one digit at a time: one, four.
2.5 = two point five
π = 3.14159… = three point one four one five nine…The digits of pi (3, 1, 4, 1, 5, 9…) never end.

Dates the American way: month first

The months are numbered 1 to 12, and a US date starts with the month: March 14 is 3/14, December 25 is 12/25. The tip shows how people say it: March fourteenth or three fourteen.

The months: 1–12

1 January
2 February
3 March
4 April
5 May
6 June
7 July
8 August
9 September
10 October
11 November
12 December

Dates in the US: the month is first

In words	In numbers	The first number
March 14	3/14	3 = March
July 4	7/4	7 = July
December 25	12/25	12 = December

Say the date

We write March 14 or 3/14. We say March fourteenth or three fourteen.

Common mistakes

fourty
forty
4 four, 14 fourteen, but 40 forty: no u!
twenty one
twenty-one
Twenty + one: use a hyphen (-).
3.14 = three comma fourteen
3.14 = three point one four
Say point. Then say one digit at a time.
March 14 = 14/3
March 14 = 3/14
In the US, the month is first.

Try the numbers and dates exercises

Try them yourself: these are the same exercises your students do in edio.

What's in the lesson

11 auto-checked exercises
3 games
1 teacher-checked task
1 real-life document
1 grammar scheme
1 set of word cards
2 audio clips
2 pictures
2 transcripts

The main objectives of this lesson are to:

count and write numbers from 0 to 100, with a hyphen in twenty-one and no u in forty
hear and say the difference between thirteen and thirty, and between the other teens and tens
read a decimal aloud, one digit at a time after the point: 3.14 is three point one four
write dates the American way, with the month first: March 14 is 3/14
name the months and their numbers, from January (1) to December (12)

Lesson 9 opens Numbers all around, the third unit of English A1.1 · Hello, World. It builds on the family words and possessive adjectives of lesson 5, now with ages (My mom is forty), and lesson 12 closes the unit with a review of numbers and dates. Pi Day makes the US date order easy to remember: March 14 is 3/14, which looks like pi's 3.14.

Students warm up with a spin wheel of number questions, ten words from pie to calendar with pictures and audio, and a picture task with three kinds of pie. They read a Pi Day poster from the shop, with a slice for $3.14, a party at 1:59 p.m. and a pi challenge, then answer true-or-false and multiple-choice questions. Next they hear Sam and Priya count the pies (an AI-voiced dialogue) and a radio host's Pi Day message. The grammar chapter has the scheme and four exercises, from choosing twelve or twenty to dragging month, day and point into sentences, each checked as students answer. In the speaking chapter, they reply to Olivia in a chat and open boxes of questions about numbers, dates and birthdays.

The homework asks for a table of dates, with numbers for July 4 and a month name for 2/9, and an anagram of words from the lesson. Last comes a recording: counting in tens, telling 13 from 30, saying pi and giving a birthday month first, for the teacher to review.

Grammar:: numbers 0–100 · saying 3.14 · dates the US way
Topic:: Pi Day · numbers · dates · pie

Teaching tips

Write 3.14 and 3/14 side by side before the reading and ask what they have in common; the poster then confirms the guesses.
Run a stress dictation with 13 and 30, 14 and 40, 15 and 50: you say one, students write it down, then pairs take over, as in the open-the-box game.
Collect the class's birthdays as US dates on the board, month first, and ask whose comes next. It practices the months and the order in one go.
Hold the poster's pi challenge in class: who can say 3.14159 the fastest, with point and one digit at a time?
Use the chat with Olivia as a model, then have pairs text each other dates like 7/4 and 12/25 and read them back in words.

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The whole course: English A1.1 · Hello, World

32 lessons for complete beginners in simple American English, from the verb to be to can and can't. Eight units cover greetings, family, numbers, home, food, daily routines, the town and free time, and each ends with a review lesson. Pictures and definitions replace translations, and the practice exercises check themselves.See the course

Unit 1 Hello!
greetings, the verb to be, countries and nationalities, yes/no questions
Unit 2 My people
family members, possessive adjectives, have got, describing people
Unit 3 Numbers all around
numbers and dates, a/an and plurals, phone numbers and prices
1. Lesson 9 · you're hereWhy is March 14 Pi Day?Numbers 0 to 100, decimals and US dates
2. Lesson 10How old is the General Sherman tree?A, an and plurals, with big numbers and How old…?
3. Lesson 119-1-1 and other numbers to knowSaying phone numbers, emails and prices
4. Lesson 12Review: 102 floors and 1,860 stepsNumbers, dates, ages and prices, reviewed
Unit 4 Home sweet home
rooms in a house, this, that, these and those, furniture, opposites
Unit 5 Food I love
likes and dislikes, present simple questions, ordering food
Unit 6 My day
telling the time, daily routines, days of the week, prepositions of time
Unit 7 My town
places in town, prepositions of place, giving directions
Unit 8 Free time
hobbies, can and can't, sports, making plans

Questions about this lesson

How do you say numbers in English?

Learn zero to twelve, then build the rest: the teens end in -teen (thirteen, nineteen), the tens end in -ty (thirty, ninety), and a ten and a digit make twenty-one or sixty-five. Say 100 as one hundred. The A1 lesson Why is March 14 Pi Day? on edio.ai lays out 0 to 100 in a single table, then puts the numbers to work counting pies.

How do you write dates in English?

In American English, the month comes before the day: March 14, or 3/14 in numbers, and July 4 is 7/4. Read short dates in that order too, so 6/5 is June 5, not May 6. Each month has its number, from January (1) to December (12), which makes 10/31 October 31.

How do you write the numbers from 1 to 100 in words?

Numbers up to twenty and the tens are single words, and the others take a hyphen between the ten and the digit: twenty-three, thirty-four, fifty-six. Watch the spelling of a few: three gives thirteen and thirty, five gives fifteen and fifty, never fiveteen or fivety. And 100 is one hundred, two words with no hyphen.

How do you say dates in English?

Say the month, then the day as an ordinal: March fourteenth, July fourth, December twenty-fifth, even when the date is written March 14. A short date in numbers can also be read just as it looks, so 3/14 becomes three fourteen. Either way, the month always comes first in American English.

How do you say decimals like 3.14 in English?

Say point for the dot, then each digit separately: 3.14 is three point one four, and 2.5 is two point five. That makes the 14 after the point one four, not fourteen, and the dot is never read as comma. Pi continues the same way, three point one four one five nine…, and its digits go on forever.

Is it "forty" or "fourty"?

The right spelling is forty, with no u, even though four and fourteen both have one. Every number built on it follows: forty-one, forty-six, forty-nine. An easy way to remember it: fourteen is simply four plus -teen, but 40 drops the u.

What's the difference between thirteen and thirty?

Besides the ending, the stress falls on a different part: thirTEEN is loud at the end, THIRty at the start. The same goes for 14 and 40, 15 and 50, through 19 and 90. When a listener isn't sure, say the digits: Fifteen or fifty? Fifteen! One, five. That exchange comes from the dialogue about a pie list in Why is March 14 Pi Day?, an A1 lesson on edio.ai.

Why is Pi Day on March 14?

Because the US writes March 14 as 3/14, and 3.14 is the start of pi, the number for circles. The idea works only with the month first: written 14/3, the date would lose the link. Pi and pie sound the same, so people eat pie on the day, and the first Pi Day was held in 1988 at the Exploratorium, a science museum in San Francisco.

How do I teach numbers and dates to beginners?

Let learners meet numbers in context before the rules, then have them choose, write and finally say them. Why is March 14 Pi Day? on edio.ai puts a poster with a $3.14 slice and a dialogue that adds up a pie order before its scheme, which covers the table to 100, the stress in 13 and 30 and month-first dates. A chat about the date and a box game end the practice.

What's a good game for practicing numbers?

A box game where each box hides a number task: a student opens one, does the task aloud, and the class checks. In Why is March 14 Pi Day? on edio.ai, the boxes ask students to count in tens to a hundred, read 7/4 and 12/25, spell F-O-R-T-Y for classmates to name, or say 13, 30, 14 and 40 while the others write down what they hear.

What's good homework for practicing numbers and dates?

Turning dates from words into numbers and back, then a short recording, covers both writing and speaking. The homework in Why is March 14 Pi Day? on edio.ai starts with a self-checking table, where July 4 becomes 7/4 and 2/9 becomes February 9, and an anagram of words like circle and calendar. Students then record themselves counting in tens, saying pi and giving their birthday month first, for the teacher.

Are there interactive exercises for numbers and dates?

Yes: online gap-fills and chats check every answer at once, which suits number spelling and dates. On edio.ai, four parts of the A1 lesson Why is March 14 Pi Day? play on its page with no account: the Pi Day poster, the dialogue about the pie list, a gap-fill for writing numbers in words, like twenty-three, and a chat about the date. The rest of the lesson unlocks after signing up.

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About this lesson

What's inside

Vocabulary

Grammar: numbers 0 to 100, decimals and US dates

Numbers 0 to 100: fourteen, but forty

Numbers 0–100

Tens + one to nine: use a hyphen (-)

Thirteen or thirty? Listen for the stress

3.14: say point, then one digit at a time

Dates the American way: month first

The months: 1–12

Dates in the US: the month is first

Common mistakes

Try the numbers and dates exercises

What's in the lesson

The main objectives of this lesson are to:

Teaching tips

Teach the whole lesson in edio

Start a free trial

Open the lesson

Teach it live or as homework

The whole course: English A1.1 · Hello, World

Unit 1 Hello!

Unit 2 My people

Unit 3 Numbers all around

Unit 4 Home sweet home

Unit 5 Food I love

Unit 6 My day

Unit 7 My town

Unit 8 Free time

Questions about this lesson

Teach this lesson with your students