Addition facts to 20: a week of ready-to-teach maths
Five days of lessons for Year 2 Algebra. Print this pack and the week is prepared: each day has a one-page plan and a student worksheet, plus cut-out cards, a mini-check and every answer.
Start here: five minutes to Monday
- Skim the week at a glance on the next page.
- Print the five days. Each day is two A4 sheets: a plan and a worksheet.
- Cut out the two card sheets once; they are reused all week.
- Open the free interactive unit on your board. Every plan tells you which picture to show and when.
- Teach straight from the plan. Timings, talk prompts, misconceptions and answers are all on the one page.
No maths background needed
This pack is written for the busy generalist teacher. Each plan explains the idea in plain words, lists the misconceptions children bring, and gives model answers, so you can walk in and teach it.
One day, one lesson
The five lessons fill a week of maths, one lesson of about 50 minutes a day. Run them in order: each day stands on the one before. Every lesson can also split into a short warm-up and a main session if your timetable runs small blocks.
The week at a glance
One lesson a day for a week. Each day stands on the day before, so run them in order.
| Day | Lesson | Children learn and do | On screen |
|---|---|---|---|
| 1 | Friends of ten | Find the pairs that make ten and know them by heart | Rainbow facts |
| 2 | Doubles and near-doubles | Learn the doubles, then nudge one more for the neighbour | The doubles engine |
| 3 | Bridge through ten | Cross ten by filling the ten first, then add the rest | Bridge through ten |
| 4 | Fact families | Turn one fact into four true sentences on a triangle | The fact family triangle |
| 5 | Subtraction you already know | Solve a take-away by recalling the addition fact | Subtraction you already know |
How the week builds
Day 1 learns the pairs that make ten; Day 2 the doubles and their neighbours; Day 3 uses ten as a bridge for sums that cross it; Day 4 turns each fact into a family; and Day 5 reads subtraction straight off the addition it already knows. It builds on adding and subtracting within 20 from Year 1, and it fuels the two-digit strategies next door.
Materials for the week (one trip)
- From the classroom: scissors, pencils, this pack printed.
- From home or the craft box: a handful of counters — buttons, dry pasta or bottle tops, about twenty per pair — and two dice for the fluency games.
- Cut out once, use all week: the ten-frames, the number-bond cards and the fact-family triangle cards in this pack. No maths equipment to buy.
Dear families
This week in maths, Year 2 learns the addition facts to twenty by heart and turns them into subtraction facts. We find the pairs that make ten, learn the doubles, bridge through ten, and read whole fact families.
Try this at home
- Play friends of ten: you say a number to ten, they say the number that makes ten. Then swap.
- Roll two dice and race to say the total. Doubles and pairs to ten are the quickest.
- Say a double, then one more: double 7 is 14, so 7 and 8 is 15.
- Turn a plus into a take-away: if 8 and 5 is 13, ask what 13 take away 5 is.
My facts this week
Fill one row a day. Tick when you can say the fact without counting.
| Day | A fact I practised | I said it fast | A take-away from its family |
|---|---|---|---|
| Monday | □ | ||
| Tuesday | □ | ||
| Wednesday | □ | ||
| Thursday | □ | ||
| Friday | □ |
Printed from the free seegongsik Addition Facts to 20 teaching pack · seegongsik.com/au/y2/algebra/AC9M2A02/pack
Friends of ten
Children find the pairs of numbers that make ten and learn them by heart. These pairs are the keys to every later strategy this week, so we meet them first and make them fast.
We are learning to
- name the number that pairs with another to make ten,
- know the pairs to ten without counting,
- show a pair to ten on a ten-frame.
Success criteria
- I can say the friend of ten for any number to ten.
- I can fill a ten-frame two ways to show a pair.
You need
The ten-frames and number-bond cards (cut-out sheet 1), one set per pair. Counters, about ten per pair. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Snap to ten Hold up some fingers; children hold up the rest to make ten. Swap and repeat quickly. Ask: “I am holding up 6 fingers. How many more make ten? Show me fast.” |
| 30 min | Fill the frame Pairs place counters on a ten-frame, then say the pair: 7 and 3, 4 and 6. They record each pair on a bond card, whole on top, parts below. Collect the five pairs together. Ask: “The frame holds ten. If 7 seats are full, how many are empty? That empty number is the friend of 7.” |
| 10 min | Rainbow race Call a number; children write its friend of ten on the worksheet as fast as they can. Ask: “I say 8, you write 2. Ready? Now 9. Now 5. Now 1.” |
Two half-sessions instead? End Session A after the frames. Start Session B with the rainbow race, then the worksheet.
Watch for these ideas
- Counting up from one every time instead of just knowing the pair.
- Forgetting that 10 and 0, and 5 and 5, are pairs to ten as well.
- Mixing up making ten with making the next number, so 6 asks for 3 instead of 4.
Answers
- Friends of ten: 6 and 4, 8 and 2, 3 and 7, 10 and 0, 5 and 5, 9 and 1, 2 and 8, 7 and 3.
- Bonds: 9 and 1 make 10; 4 and 6 make 10; 5 and 5 make 10.
- Draw: 7 dots on the frame, 3 boxes empty, so 7 and 3 make 10.
- Own pair varies: check the two numbers add to exactly 10.
Friends of ten
Every number to ten has one friend that makes ten with it. Find each friend.
Write the friend of ten
| Number | Friend of ten |
|---|---|
| 6 | |
| 8 | |
| 3 | |
| 10 | |
| 5 | |
| 9 | |
| 2 | |
| 7 |
Fill the bonds
9 and ____ make 10.
____ and 6 make 10.
5 and ____ make 10.
Draw it
Draw 7 dots on a ten-frame. Colour the empty boxes. 7 and ____ make 10.
Your own pair
Choose a number to ten. Write its friend: ____ and ____ make 10.
Doubles and near-doubles
Children learn the doubles to twenty, then spend them: a near-double is just a double and one more. The double you own does the work, and the neighbour comes free.
We are learning to
- recall the doubles to double ten,
- work out a near-double by starting from the double,
- explain that a near-double is one more than a double.
Success criteria
- I can say the doubles without counting.
- I can use a double to solve the fact next to it.
You need
Counters or two matching handfuls of pasta to build a double. The ten-frames from cut-out sheet 1. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Two of everything Spot doubles around the room: two hands, two shoes, a pair of dice. Say the doubles to ten aloud together. Ask: “Double 4 is 8. Show me double 4 on your fingers. Now what is double 5?” |
| 30 min | Build it, then one more Pairs build a double as two equal stacks and say it. Then add one counter to a stack: double 6 is 12, so 6 and 7 is 13. Record double, then near-double, each time. Ask: “You know double 8 is 16. You do not need to count 8 and 9. What is just one more than 16?” |
| 10 min | Doubles dash Call a double, then the near-double beside it; children answer on the worksheet. Ask: “Double 7 is 14. So 7 and 8 is? Tell me how the double helped.” |
Two half-sessions instead? End Session A after building the doubles. Start Session B with the near-doubles, then the doubles dash.
Watch for these ideas
- Solving 7 and 8 by counting all, instead of leaning on double 7.
- Naming the double and forgetting the extra one, so 7 and 8 stalls at 14.
- Adding two when only one number moved, so 7 and 8 overshoots to 16.
Answers
- Doubles: double 4 is 8, double 5 is 10, double 7 is 14, double 9 is 18, double 10 is 20.
- One more: double 6 is 12, so 6 and 7 is 13; double 8 is 16, so 8 and 9 is 17; double 5 is 10, so 5 and 6 is 11.
- Solve: 7 + 8 = 15, 9 + 10 = 19, 4 + 5 = 9.
- Draw: two stacks of 6 with one dot added shows 6 and 7 = 13.
Doubles and one more
First write the doubles. Then use each double to solve the near-double beside it.
Write the double
| Number | Double it |
|---|---|
| 4 | |
| 5 | |
| 7 | |
| 9 | |
| 10 |
One more than the double
Double 6 is ____, so 6 and 7 is ____.
Double 8 is ____, so 8 and 9 is ____.
Double 5 is ____, so 5 and 6 is ____.
Solve
7 + 8 = ____ 9 + 10 = ____ 4 + 5 = ____
Draw it
Draw double 6 as two stacks. Add one dot. Now it shows 6 and 7 = ____.
Bridge through ten
For sums that cross ten, such as 8 and 5, children fill the ten first, then add what is left. A full ten-frame turns an awkward sum into ten-and-something, which is no sum at all.
We are learning to
- split the second number to fill the ten first,
- add the leftover onto ten,
- solve a sum that crosses ten without counting on fingers.
Success criteria
- I can make ten first, then add the leftover.
- I can solve 8 and 5 by bridging through ten.
You need
The ten-frames from cut-out sheet 1 and counters in two colours or two shapes. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Fill me to ten Show a ten-frame with 8 counters; children say how many more fill it. This is the friends of ten from Day 1, back to earn its keep. Ask: “The frame has 9 counters. How many more make ten? So 9 always wants just one.” |
| 30 min | Fill first, then the rest Pairs solve 8 and 5: put 8 in the frame, move 2 across from the 5 to make ten, and 3 are left to ride on top, so ten and 3 is 13. Record the split. Repeat 7 and 5, 9 and 4. Ask: “How should we split the 5 so the frame fills exactly? What is left to ride on top?” |
| 10 min | Bridge it Children solve the worksheet sums, showing how they split the second number each time. Ask: “8 needs 2 to make ten. Where does that 2 come from?” |
Two half-sessions instead? End Session A after 8 and 5 together. Start Session B with 7 and 5, then the worksheet.
Watch for these ideas
- Splitting the second number the wrong way, so the frame does not land exactly on ten.
- Counting the whole ten-frame again instead of trusting that it holds ten.
- Losing the leftover, so the answer comes out as ten instead of ten-and-something.
Answers
- 8 + 5: 8 needs 2, that leaves 3, so 10 and 3 is 13.
- 7 + 6: 7 needs 3, that leaves 3, so 10 and 3 is 13.
- Table: 9 + 4 = 13, 8 + 6 = 14, 7 + 5 = 12.
- Draw: the frame full to ten with 3 on top shows 8 + 5 = 13.
Fill the ten first
Fill the ten-frame, then add what is left. Show how you split the second number.
Follow the steps
8 + 5. 8 needs ____ to make ten. That leaves ____. So 10 and ____ is ____.
7 + 6. 7 needs ____ to make ten. That leaves ____. So 10 and ____ is ____.
Now solve these
| Sum | The first number needs | Answer |
|---|---|---|
| 9 + 4 | 9 needs 1 | |
| 8 + 6 | 8 needs 2 | |
| 7 + 5 | 7 needs 3 |
Draw it
Draw 8 + 5 on a ten-frame. Fill the ten, then show the 3 on top. Answer: ____
Fact families
One addition fact hides a whole family. Put the whole on top of a triangle and the two parts below, and the same three numbers give two additions and two subtractions, all true together.
We are learning to
- build a fact-family triangle with a whole and two parts,
- write the two additions and two subtractions in a family,
- see that a double family has only two sentences.
Success criteria
- I can write the four facts in a family from one triangle.
- I can explain why a double, like 8 and 8, makes only two.
You need
The fact-family triangle cards (cut-out sheet 2), one set per pair. The worksheet, one per child.
Lesson flow (about 50 minutes)
| 10 min | Three in a triangle Show a triangle card with 5, 8 and 13, whole on top. Read up the sides for the additions, down for the subtractions. Ask: “The whole is 13, the parts are 5 and 8. What addition can you read? What subtraction?” |
| 30 min | The whole family Pairs write all four sentences for 6 and 7, then 9 and 5, then the double 8 and 8. They notice the double gives only two sentences. Ask: “You wrote 8 and 8 is 16, and 16 take away 8 is 8. Why is there no third and fourth sentence?” |
| 10 min | Family hunt Children complete the family cards on the worksheet, finding the whole first when it is missing. Ask: “Cover the whole. If the parts are 4 and 9, what is the whole? Now write its family.” |
Two half-sessions instead? End Session A after the first family. Start Session B with the double family, then the worksheet.
Watch for these ideas
- Writing 13 take away 5 is 8, then trying 5 take away 13, which these numbers cannot do.
- Putting a part on top instead of the whole, so the subtractions come out wrong.
- Expecting four sentences from a double, when the two parts are the same.
Answers
- 13 with 5 and 8: 5 + 8 = 13, 8 + 5 = 13, 13 - 5 = 8, 13 - 8 = 5.
- 14 with 9 and 5: 9 + 5 = 14, 5 + 9 = 14, 14 - 5 = 9, 14 - 9 = 5.
- 16 with 8 and 8: 8 + 8 = 16, 16 - 8 = 8 (a double makes two facts only).
- Missing: 9 + 6 = 15; family 9 + 6 = 15, 6 + 9 = 15, 15 - 6 = 9, 15 - 9 = 6.
- Triangle 7, 4, 11: 7 + 4 = 11, 4 + 7 = 11, 11 - 4 = 7, 11 - 7 = 4.
One triangle, four facts
Each family has a whole and two parts. Write the two additions and the two subtractions.
| Whole | Parts | Two additions | Two subtractions |
|---|---|---|---|
| 13 | 5 and 8 | ||
| 14 | 9 and 5 | ||
| 16 | 8 and 8 |
The last family is a double. It makes only two facts, so leave the extra spaces empty.
Find the missing number
____ + 6 = 15. The family is 6, 9 and 15. Write its four facts:
____________________________________________
Draw it
Draw a triangle for 7, 4 and 11. Put the whole on top. Write its four facts.
Subtraction you already know
Every subtraction to twenty is an addition fact in disguise. Faced with 14 take away 6, children ask what 6 needs to make 14, rather than counting backwards into the fog.
We are learning to
- solve a subtraction by recalling the matching addition,
- use a fact family to find a missing part,
- stay fast and accurate on mixed facts to twenty.
Success criteria
- I can turn a take-away into an addition I know.
- I can answer mixed facts to twenty without counting back.
You need
The fact-family triangle cards and the fact cards (cut-out sheet 2). The worksheet, one per child. Two dice for the warm-up.
Lesson flow (about 50 minutes)
| 10 min | Think the addition Show 13 take away 8. Do not count back; ask the addition that answers it. Ask: “Do not count back. Ask: 8 and what makes 13? Say the addition, then say the answer.” |
| 30 min | Fact families game Pairs turn a subtraction fact card, say the addition that solves it, and check it on a triangle. Keep every card you solve; the tallest pile wins. Ask: “You turned 15 take away 7. Which addition do you already own that lands on 15?” |
| 10 min | Mixed dash Children solve a mix of additions and subtractions on the worksheet, using doubles, bridging and families. Ask: “Which of these did you just know, and which did you work out? Tell your partner your favourite trick.” |
Two half-sessions instead? End Session A after the game. Start Session B with a quick warm-up of three families, then the mixed dash.
Watch for these ideas
- Counting back one by one and losing track once the count crosses ten.
- Reversing the numbers, writing 6 take away 14 for 14 take away 6.
- Recalling the wrong family member, so the answer is the other part.
Answers
- 13 - 8: 8 + 5 = 13, so 13 - 8 = 5.
- 15 - 9: 9 + 6 = 15, so 15 - 9 = 6.
- Solve: 12 - 7 = 5, 16 - 8 = 8, 14 - 5 = 9, 11 - 4 = 7.
- Mixed dash: 7 + 8 = 15, 13 - 6 = 7, 9 + 9 = 18, 17 - 8 = 9, 6 + 5 = 11, 14 - 7 = 7.
Subtraction you already know
For each take-away, first write the addition that helps, then write the answer.
Think the addition
13 - 8. Think: 8 + ____ = 13. So 13 - 8 = ____.
15 - 9. Think: 9 + ____ = 15. So 15 - 9 = ____.
Solve
12 - 7 = ____ 16 - 8 = ____ 14 - 5 = ____ 11 - 4 = ____
Mixed dash
| Fact | Answer |
|---|---|
| 7 + 8 | |
| 13 - 6 | |
| 9 + 9 | |
| 17 - 8 | |
| 6 + 5 | |
| 14 - 7 |
Draw it
Draw a fact-family triangle you used today. Write the take-away it helped you solve.
Ten-frames and number-bond cards
Cut out the ten-frames and the bond cards. Put counters on a ten-frame to show a number, then read the empty boxes for its friend of ten. Use a bond card to record a pair: the whole in the top box, the two parts below. One set per pair is plenty.
Ten-frames
Number-bond cards
Teacher note: the ten-frame is the tray of ten used in “Rainbow facts” and “Bridge through ten” on screen. Counters make each pair visible before the numbers do.
Fact-family triangle cards and fact cards
Cut out the triangle cards. Write the whole in the top corner and the two parts in the bottom corners. Read up the sides for the two additions, down for the two subtractions. Use the fact cards for the Day 5 game: match each subtraction to the addition that solves it.
Triangle cards
Subtraction cards
Addition cards
Teacher note: each subtraction card has a matching addition card that solves it, and the triangle cards check the family. These are the same facts as “Subtraction you already know” on screen.
What we know: addition facts to 20
Work on your own. Show your thinking if you can.
- Write the friend of ten: 8 and ____ make 10.
- Double 9 is ____.
- Double 8 is 16, so 8 + 9 = ____.
- Make ten first: 9 + 5. 9 needs ____ to make ten, then 10 and ____ makes ____.
- 7 + 6 = ____
- 9 + 4 = 13. Write one subtraction fact from the same family: ____
- The parts are 6 and 7. Write the whole, then the four facts in its family.
- Sam knows 8 + 6 = 14. Without counting, what is 14 - 6? ____
Answers and marking guide
Answers
- 2 (8 and 2 make 10).
- 18.
- 17 (double 8 is 16, and one more is 17).
- 9 needs 1, then 10 and 4 makes 14.
- 13.
- 13 - 4 = 9, or 13 - 9 = 4 (either fact from the family).
- The whole is 13: 6 + 7 = 13, 7 + 6 = 13, 13 - 6 = 7, 13 - 7 = 6.
- 8 (8 + 6 = 14, so 14 - 6 = 8).
A quick three-level guide
| Idea | Working towards | At standard | Beyond |
|---|---|---|---|
| Friends of ten and doubles (Q1, Q2, Q3) | recalls a friend of ten or a small double with counters | recalls friends of ten and doubles to twenty quickly (2, 18, 17) | derives the near-double from the double and explains the one more |
| Bridge through ten (Q4, Q5) | crosses ten by counting on | makes ten first, then adds the leftover (14, 13) | splits the second number without prompting and records the steps |
| Fact families (Q6, Q7) | writes one fact from a family with help | writes the additions and subtractions of a family | explains why a double family has only two facts |
| Apply (Q8) | counts back to subtract | solves the take-away by recalling the addition (14 - 6 = 8) | says the matching addition before answering |
Eight questions, four ideas. A child at standard answers most questions and can say the fact without counting back.
Weekly class record
Jot a tick as you move around the room; the mini-check fills any gaps. A tick a day is plenty.
| Name | Friends of ten | Doubles and near-doubles | Bridge through ten | Fact families | Subtraction facts |
|---|---|---|---|---|---|
The five columns are the five days: friends of ten, doubles, bridging, families, and subtraction facts.