Something's Hiding!
Purpose
In this activity the purpose is to find out how many tens and ones blocks are hidden from a given total.
Achievement Objectives
NA2-3: Know the basic addition and subtraction facts.
NA2-4: Know how many ones, tens, and hundreds are in whole numbers to at least 1000.
Specific Learning Outcomes
solve subtraction problems
Required Resource Materials
Blackboard or whiteboard
Place value blocks, tens and ones
Overhead projector
Activity
- Show the students you have put blocks on the OHP to represent a number but some of them are hiding (covered). Ask them to work out how many are hiding.
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All my blocks together show 78, but some of them are hiding.
How many are hiding?
- After a time for thinking, have students share their answers and their thinking, recording some of these on the board.
- Uncover the hiding blocks, and count them to show students both the number hiding and the total number.
- Repeat the activity with a different number of blocks hidden.