1. Objective To begin to think about number and algebra in relation to areas of compound shapes.

2. I will be successful if: -I am able to express areas using algebra -I am able to simplify algebraic expressions

3. So this shape has area area b area a Adding Areas area b area a This has an area of a a+ b and this has an area of b

4. Think about this shape; Or like thisIt could be made like this 2a2a + 2b a + b 2a + 2b = 2(a + b)

5. How many different ways can you find of writing the areas of these shapes? a) b) c) d) e) f) g)

6. How did you find g? If this has area a and I take away area bI’m left with area a - b This has area a + (a – b) Which is time2a - b 4(2a - b) ORtimes1 234

7. So now can you do these? Remember to write them in as many different ways as you can find!! a) b) c) d) e) f) g) h)

8. The 5 ‘easy’ Tak-tiles If the area of the square is a area a and the area of the quadrant is b area b Then the area of this shape is b+ab+ OR a + 2b So what about these? area a + 2b area 4a - 2barea 3a - barea 2a

9. MISSION IMPOSSIBLE Mr Ranson’s safe

10. YES! MY KEY WORKS This has area 8a8a+3b3b-4b4b Which is 8a - b OR a + 2b 4a - 2b 3a - b + + ________________ a + 4a – 3a +2b - 2b - b Which is 8a - b ________________

11. Can you do this shape in the same way? area 11a+3b3b- 2b2b 11a + b a + 2b 2a2a + + 3a - b 4a - 2b a + 2b + + ________________ 11a + b