How Many Left 2 Year 1 Addition and Subtraction Learning Video Clip

Step 12: How Many Left 2 Year 1 Addition and Subtraction Learning Video Clip

Dot the Dinosaur has noticed that Stan the Stegosaurus isn’t acting like his usual self; it looks like that everyone has forgotten about his birthday! Help Dot cheer Stan up by using your knowledge of subtraction!

More resources for Autumn Block 2 Step 12.

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Discussion points for teachers

1. How many butterflies are left?
Discuss how many butterflies there were originally. How many have flown away? How could we check? Is there a way we could write this calculation down?
2

2. How many butterflies are left now?
Discuss using the facts and answer from the previous question - how many more have flown away now?
0

3. How many boulders are left?
Discuss how many boulders there were originally. How many has Dot moved? How could we check? Is there a way we could write this calculation down?
3

4. How many more boulders will Dot need to move so that there are none left?
Discuss how many boulders were left from the previous question. How many do we need to subtract in order to get to ‘0’?
3

5. How many bats are left?
Discuss how many bats there were originally – how many have flown away? How could we check? What number would need to go in the calculation shown? What does the ‘–’ and ‘=‘ symbol mean?
4

6. How many bats are left now?
Discuss how many bats are left now using the knowledge you have gained from the previous question?
1

7. How many scorpions are left?
Discuss how many scorpions there were originally. How many have been scared away first? How many were scared away after? Are there any left at the end? Is there a way we could write this calculation down?
0

8. How many piles of soil could Dot have dug up each on each go?
Discuss how many piles of soil there were originally. If Dot dug up all the piles of soil in two goes, what does this tell us? What number bonds to 8 can you think of? Does it matter that the ‘=‘ comes first? This question is open-ended for the children to explore.
Accept various answers, as long as (when subtracted from 8) both numbers equal 0. Various answers, for example: 0 = 8 – 5 – 3

Optional discussion points for teachers

1. What does the ‘–’ symbol carved on top of the cave mean?
Discuss how it is different to the ‘+’ symbol we have already come across. Will our numbers get bigger or smaller when we use this symbol? How is this symbol used in a calculation?

2. Does it matter in which order we put out numbers in when subtracting?
Discuss how to placement of numbers will affect the number we get at the end. How is this different to addition?

3. Does it matter if the equal sign comes first?
Discuss how if the ‘=‘ sign is shown first, the other numbers we are subtracting will still need to be placed in the same order from left to right. E.g. 8 – 7 = 1, 1 = 8 – 7

National Curriculum Objectives

Mathematics Year 1: (1C1) Represent and use number bonds and related subtraction facts within 20

Mathematics Year 1: (1C2a) Add and subtract one-digit and two-digit numbers to 20, including zero

Mathematics Year 1: (1C4) Solve one-step problems that involve addition and subtraction, using concrete objects and pictorial representations, and missing number problems such as 7=_________ 9

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