1. Say 1 more and 1 less than a 2-digit number
Place Value
Say 1 more and 1 less than a 2-digit number
Objectives
Day 1
Find one more and one less than any 2-digit number.
Day 2
Before teaching, be aware that:
On Day 1 children will need mini-whiteboards and pens. 100 bead bar, tags, 0–100 beaded line (see resources), 1–100 grid
On Day 2 children will need mini-whiteboards and pens. 0–100 beaded line (see resources)
Year 1

2. Say 1 more and 1 less than a 2-digit number
Place Value
Say 1 more and 1 less than a 2-digit number
Starters
Day 1
Count to 100 using a grid (pre-requisite skills)
Day 2
Count to 100 using a bead bar (pre-requisite skills)
Choose starters that suit your class by dragging and dropping the relevant slide or slides below to the start of the teaching for each day.
Year 1

3. Say 1 more and 1 less than a 2-digit number
Place Value
Say 1 more and 1 less than a 2-digit number
Starter
Count to 100 using a grid
Pre-requisite skills – to use this starter, drag this slide to the start of Day 1
Show the 1–100 grid on slide 3. Count in 1s from 1 to 100, pointing to each number and emphasising the multiples of 5: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11…. Repeat so that more children join in.
Year 1

4. Year 1

5. Place Value Say 1 more and 1 less than a 2-digit number Starter
Count to 100 using a bead bar
Pre-requisite skills – to use this starter, drag this slide to the start of Day 2
Use the bead bar to support counting in 1s to 100, emphasising the multiples of 5: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11…. Repeat with the 1–100 grid, then try counting backwards and ending with ‘blast off!’ Ask children to join in with you as you count to 100 in 10s. Ask them to raise two hands for each 10s number. Repeat, this time pointing to the numbers on the 1–100 grid (children still raise hands for 10s numbers).
Year 1

6. Say 1 more and 1 less than a 2-digit number
Place Value
Say 1 more and 1 less than a 2-digit number
Objectives
Day 1
Find one more and one less than any 2-digit number.
Year 1

7. Count on in tens from zero.
Day 1: Find one more and one less than any 2-digit number.
Count on in tens from zero.
Year 1

8. Day 1: Find one more and one less than any 2-digit number.
What number came after 40?
What number was before 40?
Count on in ones from 30 to 45.
Year 1

9. What number comes after 60? What number comes before 60?
Day 1: Find one more and one less than any 2-digit number.
What number comes after 60?
What number comes before 60?
Count on in ones from 50 to 65.
Repeat with each multiple of 10.
Year 1

10. Day 1: Find one more and one less than any 2-digit number.
What came after 90?
Count on in ones from 80 to 95.
What came before 90?
Count on in ones from 80 to 95.
Repeat with each multiple of 10.
Year 1

11. Day 1: Find one more and one less than any 2-digit number.
If I slide one more bead across to join them, how many will there be?
How many beads am I showing? 45 46 45
46 is one more than 45. 46
Year 1

12. If I put one bead back, how many will I be showing then?
Day 1: Find one more and one less than any 2-digit number.
If I put one bead back, how many will I be showing then? 44 45
44 is one less than 45. 44
Year 1

13. Day 1: Find one more and one less than any 2-digit number.
Repeat for the numbers
1 more and 1 less than 38:
Year 1

14. Day 1: Find one more and one less than any 2-digit number.
Repeat for the numbers
1 more and 1 less than 63:
Year 1

15. Which number have I drawn a tag on ?
Day 1: Find one more and one less than any 2-digit number. 36 38 37
What comes after 37?
What comes before 37?
Which number have I drawn a tag on ? 37 36 38
Year 1

16. Mark the numbers on the grid.
Day 1: Find one more and one less than any 2-digit number. 48 53
Now mark 48 on the line.
What comes before and after?
What comes before 53? What comes after 53?
Can you mark 53 on the line with a tag?
Today would be a great day to use a problem-solving investigation – Stop the Bus! – as the group activity, which you can find in this unit’s IN-DEPTH INVESTIGATION box on Hamilton’s website.
Alternatively, children can now go on to do differentiated GROUP ACTIVITIES. You can find Hamilton’s group activities in this unit’s TEACHING AND GROUP ACTIVITIES download.
WT/ARE: Give clues for children to find numbers on a 1–100 grid. Describe each number’s position.
ARE/GD: Make a 2-digit number and mark it on a 0–100 beaded line.
Mark the numbers on the grid.
Year 1

17. The Practice Sheet on this slide is suitable for most children.
Differentiated PRACTICE WORKSHEETS are available on Hamilton’s website in this unit’s PROCEDURAL FLUENCY box.
WT/ARE/GD: One more/one less
Challenge
Year 1

18. Say 1 more and 1 less than a 2-digit number
Place Value
Say 1 more and 1 less than a 2-digit number
Objectives
Day 2
Find one more and one less than any 2-digit number.
Year 1

19. Now count on one. Where do we land? Where is 23 on the beaded line?
Day 2: Find one more and one less than any 2-digit number.
+ 1 23 24
23 + 1
= 24
Now count on one. Where do we land?
Where is 23 on the beaded line?
Look at this this calculation.
Year 1

20. Look at the rest of these calculations.
Day 2: Find one more and one less than any 2-digit number.
Look at the rest of these calculations.
23 + 1
34 + 1
29 + 1
99 + 1
24 – 1
67 – 1
60 – 1
80 – 1
Work through each of these calculations: ask children to find the first number on the beaded line before counting on or back one bead.
Draw the hop and label +1 or -1.
Year 1

21. What if we took the 1 away again.
Day 2: Find one more and one less than any 2-digit number.
What if we took the 1 away again.
Where would we land?
Back on 23!
= 24
We had 23 then
added 1.
= 23
Use numbers 23 or 24 to fill the blanks in these sentences.
24 is one more than 23
23 is one less than 24
Year 1

22. What if we took the 1 away again.
Day 2: Find one more and one less than any 2-digit number.
Back on 46!
What if we took the 1 away again.
Where would we land?
= 47
We had 46 then
added 1.
= 46
Children can now go on to do differentiated GROUP ACTIVITIES. You can find Hamilton’s group activities in this unit’s TEACHING AND GROUP ACTIVITIES download.
WT/ARE: Make a 2-digit number and find one more/one less than this number.
GD: Find numbers to make a blank number statement true.
Fill in the blanks using 46 or 47.
47 is one more than 46
46 is one less than 47
Year 1

23. Year 1 The Practice Sheet on this slide is suitable for most children.
Differentiated PRACTICE WORKSHEETS are available on Hamilton’s website in this unit’s PROCEDURAL FLUENCY box.
WT/ARE/GD: Missing numbers – one more/one less
Year 1

24. Say 1 more and 1 less than a 2-digit number
Place Value
Say 1 more and 1 less than a 2-digit number
Objectives
Day 1
Find one more and one less than any 2-digit number.
Day 2
You can now use the Mastery: Reasoning and Problem-Solving questions to assess children’s success across this unit. Go to the next slide.
Year 1

25. Problem solving and reasoning questions
Find these numbers on a bead string:
13, 26, 48, 71 and 95
What are the numbers after…
(a) 46? (b) 59?
(c) 80?
What are the numbers before…
(a) ? (b) 70?
(c) ?
Mystery number
I add one to my number and get 75.
What is my number?
Jim takes one away from his number and gets 52.
What is Jim’s number?
Year 1