Ten more ten less explained

Homework asks for ten more than 47, or ten less than 83 - and your child starts counting from one on their fingers. The answer is right eventually, but the path is exhausting. This guide is for Australian parents who want the place-value mental jump: change the tens digit, leave the ones alone, and skip the long recount.

It sits beside place value explained (the tens/ones system) and skip counting (equal jumps of 2s, 5s and 10s). Those pages own the overview and the count-by chant; this page owns ten more / ten less from any starting number. Related: number bonds, addition, subtraction, zero holds the place, and Year 1–Year 3 maths.

The big idea: tens move, ones stay

Ten more means add one ten. Ten less means take away one ten. In a two-digit number, that usually means:

• the ones digit does not change
• the tens digit goes up or down by one

Examples:

• 47 → ten more → 57 (4 tens become 5 tens; 7 ones stay)
• 47 → ten less → 37 (4 tens become 3 tens; 7 ones stay)
• 30 → ten more → 40 (ones are already zero - they still stay)

Say it aloud: "Same ones. One more ten" or "Same ones. One less ten."

That is place value doing useful work - not a party trick. Australian Curriculum Mathematics (version 9) builds place value and mental strategies with tens strongly from Year 1 into Year 3 (Year 1–Year 3). Teachers may say ten more, ten less, add a ten, or subtract a ten - echo their phrase.

How this differs from place value and skip-counting

Place value explained is the full tens/ones/hundreds overview - ±10 is one habit among several. Skip counting owns equal jumps (including 10, 20, 30…) as a bridge toward times tables. Counting by tens from zero is related - but homework often asks ten more than 47, which is not the chant from the start.

This page is the ±10 deep dive: ones stay put, tens digit shifts, hundred-chart moves, money games, and mix-ups when numbers cross 100. If your child names tens and ones but still recounts from 1 for every "ten more," start here.

Show it before you say it

Materials beat worksheets for the first week.

Base-ten bundles or sticks. Build 47 as four tens and seven ones. Add one more ten stick → 57. Remove one ten stick → 37. Point: "The ones pile did not move."

Hundred chart. Find 47. Move down one row for ten more (57). Move up one row for ten less (37). Sideways moves change ones; vertical moves change tens. That picture sticks.

Place-value chart. Write 4 | 7. Change only the tens box: 5 | 7 or 3 | 7. The ones box is untouched on purpose.

Once the story is clear, try the same jump without materials - still naming "same ones, one more ten."

Crossing a hundred (and other sticky spots)

Two-digit jumps feel tidy until the tens digit runs out of room - or a hundred joins the story.

97 + 10 = 107. Ones stay 7; tens go past 9, so you need a hundred. Expanded talk helps: 9 tens + 1 ten = 10 tens = 1 hundred + 0 tens, plus 7 ones → 107. Zero holds the place matters here so 107 does not collapse into 17.

103 − 10 = 93. Ones stay 3; you are removing one ten from 10 tens (which is 1 hundred + 0 tens). Children who only "count back ten" on fingers often land on the wrong ones digit.

100 + 10 = 110 (not 200, not 1010). Ten more than one hundred is one hundred and ten - still "same ones (zero), one more ten," now living in three-digit land.

At home: practise a short bridge set deliberately - 95, 96, 97, 98, 99, 100, 101 - with ten more and ten less each way. Do not wait until a worksheet springs the trap cold.

Year by year: where ±10 shows up

Year 1 - numbers to at least 100; early ten more / ten less on a hundred chart or with materials (Year 1 maths).

Year 2 - place value to at least 1,000; mental tens strategies; crossing into three-digit answers (Year 2 maths).

Year 3 - ±10 should feel automatic so attention can go to harder addition and subtraction (Year 3 maths).

If wobbles sit inside a broader worry, see Is my child behind in maths?, maths anxiety, and homework without tears.

Common mix-ups (and kinder fixes)

Recounts from 1 every time. Fix: cover the ones digit. Ask "one more ten than 4 tens?" Then uncover ones - still 7. Rebuild once with sticks if needed.

Changes the ones instead of the tens. Fix: hundred-chart rule - "ten more is down a row, not sideways." Sideways is ±1.

Says 47 + 10 = 57 but writes 67. Fix: place chart - change only the tens box; read the full number aloud.

100 + 10 → 200 or 1010. Fix: "one hundred is 10 tens; one more ten makes 11 tens = 110." Build with a hundred flat + one ten stick.

97 + 10 said as 107, written 170. Fix: H | T | O boxes; keep placeholder zeros honest (zero holds the place).

Confuses ten more with skip-counting from zero. Fix: start mid-number (23, 68, 91). Both useful; different jobs (skip counting).

Only practises tidy tens (20, 30, 40). Fix: mix in 34, 58, 76, 99 so non-zero ones stay visibly unchanged.

Home games that do not feel like worksheets

Hundred-chart hop. Finger on a start number. Say "ten more" or "ten less." Child moves one row and names the new number. Swap roles.

Mystery cover. Write a two-digit number; cover the ones. Child changes only the tens digit for ±10, then peels to check ones stayed put.

Money tens. Use ten-cent (or $1) coins as tens in play money - more context in money maths at home. Add or remove one ten-coin; ones-cents stay.

Bus stop. "46 people. Ten more get on - how many?" Short stories; celebrate the tens story, not speed.

Crossing-100 dash. Cards near 100 (95–105); ten more / ten less each. Stop while friendly.

Keep each game under ten minutes. Celebrate the story ("ones stayed seven"), not only the digits.

A simple weekly home routine

1. Two minutes of naming - pick one number; say ten more and ten less with "same ones…"
2. Four minutes of showing - hundred chart or base-ten sticks for one mid-number and one near-100 number.
3. Three minutes of a tiny game - chart hop or mystery cover.

Stop while it is still friendly. Number bonds to 10 should feel settled enough that you are not also re-teaching "what is a ten" in the same five minutes.

How this links to other guides

• Place value explained - system overview; this page is the ±10 zoom-in
• Skip counting explained - equal jumps including 10s; different from ten more from a mid-number
• Zero holds the place - empty places when ±10 lands on 107 or 110
• Addition / Subtraction - where ±10 sits as a mental strategy
• Number bonds - early pairs under place language
• Year 1–Year 3 maths - year checklists
• Money maths at home / Maths help hub

Ask the teacher: "For ten more / ten less, do you want hundred-chart, place-value chart, or materials first?" Matching home language reduces crossed wires.

FAQ

Why not just count on ten fingers?

Fine once as a bridge - it does not scale. Move quickly to "same ones, one more ten" so larger mental work has a place-value habit underneath.

Is ten more the same as skip-counting by tens?

Related, not identical. Skip-counting often chants from 0 or 10. Ten more starts at any number (47, 83, 96) and adds exactly one ten. Homework usually means the second.

What if my child can do ten more but not ten less?

Common. Practise ten less up a row on the hundred chart and by removing one ten stick. Keep ones unchanged so the only story is "one less ten."

How is this different from place value explained?

Place value explained is the system overview. This page is only ten more / ten less - tens shift, ones stay, chart/money games, and crossing-100 mix-ups.

When should we talk to the teacher?

If, well into Year 2, your child still recounts from 1 for every ±10, routinely changes the ones digit, or cannot explain 97 + 10 after chart or materials practice.

A calm next step

When "same ones, one more / one less ten" feels settled - including a few jumps across 100 - and you want a wider number-skill snapshot at home, Ziado's free check is a one-off, roughly 10-minute adaptive diagnostic with partial results only - no account and no card. The full placement unlocks after signup. It is not NAPLAN practice and it is not the full product; Ziado's ongoing path is adaptive maths (Foundation–Year 6) plus phonics reading (Foundation–Year 4). Explore Ziado maths if you want practice that can meet place-value and early number skills at the right step. Individual and Family plans, if you continue later, start with a 14-day free trial of the full app — see pricing for current plans.

Ten-more jumps sit on top of knowing what a ten is — see bundling tens explained.