📖 Definitions

Words used in education, explained for grown-ups. No teaching jargon — just what each word means and a quick example. 46 words so far.

🔢 Numbers & Place Value

The words behind September's work with numbers up to 10,000.

Digit: Any one of the ten symbols 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Numbers are built out of digits the way words are built out of letters.; Example: 4,301 is made of the digits 4, 3, 0 and 1.
Numeral: The name we write down for a number — either in digits or in words. The number itself is the amount it stands for.; Example: 4,301 and "four thousand, three hundred one" are two ways of writing the same numeral.
Place value: How much a digit is worth because of where it sits in a number. Move it one spot and its value changes completely.; Example: In 4,301 the 4 sits in the thousands place, so it means 4,000 — not 4.
Place value chart: A simple table with columns for ones, tens, hundreds and thousands, so a number can be dropped into the right columns and read easily.
Whole number: A plain counting number with no parts or pieces attached — nothing after a decimal point and no fractions.; Example: 5, 340 and 10,000 are whole numbers.
Expanded notation: Writing a number by pulling it apart into the value of each digit, then showing those pieces being added.; Example: 4,301 = 4,000 + 300 + 1. Backwards: 2,000 + 400 + 60 = 2,460.
Ascending order: Listing numbers from smallest to largest.; Example: 1,200 then 2,300 then 4,500.
Descending order: Listing numbers from largest to smallest.; Example: 4,500 then 2,300 then 1,200.
Number line: A straight line with numbers marked in order, like a ruler. It makes it easy to see which number is bigger and to spot missing numbers.
Sequence: A list of numbers that follows a rule. Finding the rule is the puzzle.; Example: 5, 10, 15, 20 … follows the rule 'add 5 each time'.
Compare: Find out which of two numbers is bigger, which is smaller, or whether they are the same.
Greater than and less than: The symbols > and <. The open end always faces the bigger number.; Example: 3,500 > 2,400 means 3,500 is greater than 2,400.

➕ Adding & Subtracting

October's learning focus — and the words the activities use.

Addition: Putting numbers together to find a total. The answer is called the sum.; Example: 2,000 + 5,000 = 7,000 people at the festival.
Sum: The answer to an addition problem.; Example: 1,234 + 2,345 = 3,579, so 3,579 is the sum.
Subtraction: Taking one number away from another, or finding the gap between two numbers. The answer is called the difference.
Difference: The answer to a subtraction problem — how far apart two numbers are.; Example: 500 − 385 = 115, so the difference is 115.
Regrouping (carrying): When a column in an addition problem adds to 10 or more, the extra ten is 'carried' into the next column to the left.; Example: 6 + 8 = 14: write 4 in the ones place and carry 1 ten over.
Regrouping (borrowing): When the top digit is too small to subtract from, you borrow ten from the next column over. Zeros make this trickier, because you may have to borrow across two columns.; Example: In 4,000 − 1,234 the zeros have nothing to give, so the borrow starts at the thousands.
Tracking digits with the same place value: Keeping ones under ones, tens under tens and hundreds under hundreds when you add or subtract, so you never add tens to ones by mistake.; Example: When adding 345 + 2,134, the 4 in 345 is tens, so it lines up under the 3 in 2,134 — also tens.
Number sentence: A maths statement written with an equals sign, the way a sentence is written with a full stop.; Example: 385 + 115 = 500.
Missing number: A number hidden inside a number sentence. Subtraction is usually the way to find it.; Example: 385 + ___ = 500, so ___ = 500 − 385 = 115.
Word problem: A question told as a story. The trick is spotting the maths hiding inside the words.
Extra information: A number the story gives you that you don't actually need to answer the question. Teachers include these on purpose to check your child read carefully.; Example: 'The school has 400 students' doesn't help when you're working out how much money is left over.
Two-step problem: A problem that needs two operations to solve, such as adding first and then subtracting.; Example: Add the cans two grades brought, then subtract that from the total collected.

🎯 Estimating

Why 'about right' is often the point.

Estimate: A sensible 'about how much' answer. You don't need an exact number to decide whether $20 will cover two toys that are about $9 and about $8.
Front-end strategy: An estimating shortcut: use only the biggest place in each number and ignore the rest for a quick answer.; Example: 3,456 + 2,345 is about 3,000 + 2,000 = 5,000.
Compensation: Nudge a number to a friendly one, work it out, then adjust. It gives a closer estimate than the front-end strategy.; Example: 398 + 456 is easier as 400 + 456 = 856 — and the exact answer, 854, is right next to it.
Rounding: Making a number into the nearest friendly ten, hundred or thousand.; Example: 398 rounds to 400; 2,998 rounds to 3,000.
Exact answer: The precisely correct number. Estimates are fine for quick decisions; exact answers matter when precision counts, like making change or measuring medicine.

⏰ Telling the Time

September's clock practice, word by word.

Analog clock: A clock with hands that point to the numbers around a circle.
Digital clock: A clock that shows the time as numbers rather than hands.; Example: It shows 2:50 instead of pointing to it.
Hour hand and minute hand: The short hand points to the hour; the long hand points to the minutes. Kids often read the short hand as minutes by mistake.
O'clock: Exactly on the hour, with the long hand pointing at the 12.; Example: 3:00 is three o'clock.
Half past: 30 minutes after the hour — the long hand points straight down at the 6.; Example: Half past 4 is 4:30.
Quarter past and quarter to: 15 minutes after the hour, or 15 minutes before the next hour.; Example: Quarter past 2 is 2:15; quarter to 3 is 2:45.
Counting by fives: 5, 10, 15, 20, 25 … — the way the big marks around a clock face are read to get the minutes.
Elapsed time: How long something took from start to finish.; Example: From 2:15 to 3:00 is 45 minutes of elapsed time.
AM and PM: AM is the morning, PM is the afternoon and evening.

📅 Calendar & Dates

The other September skill — reading a calendar.

Reading a calendar: Finding information on a calendar: what day of the week a date falls on, how many days until something, or what comes before and after.
Date: One named day on the calendar — the month, the day and the year together.; Example: October 9, 2026.
Month: One of the 12 parts of a year. This site is organised month by month so you can see what we're up to right now.
School year: The year our classes run from September to June. We're in the 2026–2027 school year.

🏫 Words used in Education

Handy if you're wondering what a code on this site means.

Learning outcome (like 4.N1): The specific skill the province expects Grade 4 students to learn. The code reads as: 4 = grade 4, N = Number, 1 = outcome one.; Example: 4.N3 is addition and subtraction to 10,000.
Curriculum goals: The list of what we're working on that month, so you can see the reason behind each activity.
Practice activity: An online page of questions your child can do at home — nothing to print, nothing to hand in, just practice with instant feedback.
Coming soon: That subject is planned, but the lessons haven't been added yet. Math is filled in first.

Can't find a word? Let us know and we'll add it — it probably means other parents are wondering too.