Today we are going to be subtracting by counting back. You will need 20 pencils or felt tips to count with, a number line or 100 square and your Maths No Problem workbook 1A.
First look at this problem and decide how you think we could work it out. Could you use your pencils to help you?
Is there a way to subtract without counting the whole group? Can you count back? If you have 15 pencils and take away 3 you could count back out loud each time you remove one – ‘15 – 14…13…12′.
My friend said that when you subtract from a number, the number usually gets smaller. Is this true?
Now try these using your pencils. Remember to count back as you take a pencil away.
15-2=
17-3=
14-4=
Now have a go at pages 128-129 in your work book: Worksheet 4 -subtract by counting back. This time we will count back on a number line.
Finally, at some point today click on the link to have a go at this game:
https://www.topmarks.co.uk/learning-to-count/helicopter-rescue
Choose play game, count on and back and numbers 1-20 to start you off.