Primary 1 Numbers up to 100

Keywords

Use these words when your child explains a number, a pattern or a question. Point to a real example before asking for a definition.

Digit

One symbol from 0 to 9. The digits in 47 are 4 and 7.

Numeral

A number written with digits, such as 47.

Number word

A number written in letters, such as forty-seven.

Ones

Single units. In 47, the 7 means seven ones.

Tens

Groups of ten ones. In 47, the 4 means four tens, or 40.

Hundred

Ten tens, or 100 ones. One hundred is written 100.

Place value

The value of a digit because of its position in a number.

Greater than / less than

Ways to compare amounts. 63 is greater than 59; 59 is less than 63.

Sequence

Numbers in an order that follows a rule, such as 2, 4, 6, 8.

Ordinal number

A position word, such as first, second or third.

Possible value

A number that meets every condition in a question.

Question clues: “More than” and “less than” set limits; “altogether” asks about a total; “from the left” or “from the right” tells where to start counting.

Write numbers in words

Learn the small number names first. Then connect the teens and tens to the numbers your child can build and count.

Important: Use a hyphen without spaces for 21–99 when there is a ones part: twenty-one, fifty-two. Whole tens such as forty and ninety have no hyphen. Watch the spellings fourteen, forty, nineteen and ninety.

Common mistake: Writing “fourty” or “ninteen”, or leaving out the hyphen in forty-two. Say the tens and ones aloud, then check the spelling.

Ask: “How many tens do you hear? What ones word comes after it?”

Place value and placing digits

Base-ten blocks help a child see what each digit is worth: a small unit is one, a rod is ten ones, and a flat is one hundred. Exchange ten ones for a ten; the amount does not change.

Important: 100 is one hundred, zero tens and zero ones. It is the only three-digit number in this guide. Do not read 47 as 74: the position changes each digit’s value.

Common mistake: Reading 47 as 74, or treating a ten rod as one unit. Build the number and name the tens and ones before writing it.

Ask: “Can you trade ten ones for one ten? How many tens and ones do you have now?”

Comparing numbers

For single-digit numbers, compare the quantities directly. For two-digit numbers, compare the tens first. If the tens are equal, compare the ones.

Common mistake: Choosing 59 over 63 because 9 is greater than 3. Compare the tens first: 6 tens is greater than 5 tens.

Ask: “Which place should we compare first? What if those digits are the same?”

Number sequences

Look at how one number changes to the next. Count forward or backward in equal steps, then check that the same step works twice.

Common mistake: Guessing the next number after checking only one pair, or adding when the pattern decreases. Check the same jump between at least two pairs.

Ask: “What changed each time? Can you show the jumps on a number line?”

Ordinal numbers

Ordinal words tell us a position: first, second, third, fourth, fifth, sixth, seventh, eighth, ninth and tenth. Always say where counting starts.

Important: “Second” tells which position, not that there are two children. Turning around changes the direction of counting.

Common mistake: Starting at the left when the question says “from the right”, or treating “third” as three children. Point to the starting end and count positions one by one.

Ask: “Where do we start counting? Can you point to each child as you count?”

Printables

Use these sheets to build numbers with hundreds, tens and ones, then record each digit in its place-value column.