This document outlines different mental math strategies and provides examples of how they can be used to solve word problems. It discusses counting on or back, rounding and adjusting, partitioning, re-ordering, inverse operations, and factors. It then describes how students in different year levels demonstrate these strategies. For example, year 2 students use counting on, year 3 uses re-ordering, and year 6 solves a word problem using a strategy and the RUCSAC procedure to show their work.

1. Mental Strategies
Erasmus Training
Wednesday 7th February 2018

2. Mental Strategies
WALT:
• Look at the different Mental Strategies
• See practical application of strategies
• Listen to Year 6 children using a Mental
Strategy within a word problem

3. The strategies
Counting on or back
Rounding and adjusting
Partitioning
Re-ordering
Inverse operations
Factors

4. Counting on or back
3+2, 7+1, 6-2
14+3, 47-2, 30+20, 61-20
16-12, 35+17, 420+310
3700-1200, 7.8-0.3, 7.8+0.7

6. Year 2
Counting On strategy

7. Re-ordering
1 add 7 is the same as 7 add 1
3p+28p is the same as 28p+3p
310+420=420+310, 7x4=4x7,
4+9+6=6+4+9, 9+4+8=9+8+4
9+4+8+9=9+9+8+4,
0.7+0.8+0.3= 0.7+0.3+0.8

9. Year 3
Re-ordering strategy

10. Inverse operations
10-6 is the same as 6 and how
many make 10
16-12=12+__=16, 3x4=12 so
12/4=3 and 12/3=4
301-180=180+___=301
5000/250=250x___=5000

12. Year 5
Inverse Operations
strategy

13. Partitioning
27+5=27+3+2
41-6=41-1-5
35+17=35+10+7=45+7=52
78-43=78-40=38-3= 35
330+210=330+200+10
14x8=(10x8)+(4x8)
3.6+2.2=3.0+2.0+0.6+0.2

15. Year 4
Partitioning strategy

16. Rounding and adjusting
7+8=7+7+1
27+9=27+10-1
70+80=70+70+10
6x4=double (6x2)
700+800=700+700+100
840+190=840+200-10

18. Year 6
Rounding and
Adjusting strategy

19. Factors
35x4 = 70x2
80x6 = 8x10x6 or 6x8x10

21. Year 7
Factors strategy

22. Year 6
Children will demonstrate the use of
Mental Strategies within a Mental
Calculation using the RUCSAC
procedure.

24. Now it’s you turn!!
In small groups complete
the given word problem
using an appropriate
strategy and the RUCSAC
procedure.