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
