Stage 1 Thinking mathematically resource

Sam and Holly's problem

Read about Sam and Holly playing a game

Sam and Holly were playing with combinations of numbers that make 10. They started by getting out 10 blocks.

10 blocks organised in 2 rows of 5 (like a 10 frame)

Then, Sam covered some of the blocks and Holly had to work out how many were missing.

Some of the 10 blocks have been covered up by a mug. The uncovered blocks are all in a bunch.

Holly decided she to organise what she could see to help her work out what was missing.

The uncovered blocks are now organised with one row of 5 and the next row has 2.

She imaged a ten-frame in her head and organised the blocks. This helped her see she needed 3 more to make 10.

Holly and Sam kept taking turns like this until Holly asked Sam if they could make it more challenging for them.

Watch the video to see what happened next

Transcript

Hi Holly.

Hi.

Do you want to play game?

Yeah.

Sure, so we're going to start off - can you just tell me how many are here?

Ten.

Alright, so we, so I'm gonna take some put it under a cup ok. That way it will make it a bit more harder for my brain. Sure, alright, so I'll do this like say, close your eyes. OK, say. Don't peek, close your eyes?

Alright, so how many do you think is left? How many do you think are in here?

A problem for Holly

Sam made this for Holly to think about.

There are 2 mugs covering some blocks. 3 are visible.

Instructions

Can you help Holly work out how many blocks are hidden?
Can you help her work out how many of the hidden blocks might be underneath each cup?
What are all the possibilities? Record your thinking.

Discuss

What possibilities did you find?
Could you work out exactly what Sam put under each cup for Holly?
- Why?
- Why not?

Share/submit

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