More Revision Rides Again

MORE REVISION RIDES AGAIN20040202


This sheet should be done entirely without calculators. The idea is to help remember some numbers and some rules and to apply some skills.


1   The number of millimetres in an inch is __________________

2   A mile is _____________ kilometres to 3 d.p.

3    10 gallons is _____________ litres

4   (-21) ²    = ___________    22 ²    = __________  -(23) ²    = ___________

5    27²   - 23²    =  50 x ____  = _____          28²  - 22²    =  50 x  ______  = 300

6    A sum times a _______________ is the _______ of two ___________s

Using this rule and without knowing any extreme squares:

7      57²  -  43²       = 

8      77²  -  23²       = 

9      143²  -   57²    = 

AND, using the same idea in reverse (which is a hint in both directions)

10     (28 + 7) (28 - 7)   =

11      107  x  93           =

12      89  x  71             =

If you’re up to this, use matrices to solve                 

 .           15 x  –   9 y    =   7

 .           17 x  +  11 y   = -3

help: the determinant is 15x11-(-9)x17 = 318

© David Scoins 2017