Times Tables Tricks for the 8 and 9 Times Tables
Momo the monkey shares two tricks for the hardest times tables. For the nines, the tens digit is one less than the number and the two digits add up to 9 (9 × 7 = 63). For the eights, double, double and double again (8 × 6 = 48). Then work out 8 × 7 yourself, and learn the 5, 6, 7, 8 trick.
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1:37Estimating Answers by Rounding
Which is the best estimate for 49 × 21? Momo the monkey rounds each number to something friendly (50 × 20) to get about 1,000 in seconds. Learn to estimate before you calculate and to use an estimate to catch mistakes, then estimate 398 + 203 yourself.
1:59Order of Operations (BIDMAS)
Fizz the fox thinks 3 + 4 × 2 is 14, but Professor Hoot the owl shows why it is 11. Learn BIDMAS (brackets, indices, divide and multiply, add and subtract), then try (10 − 4) × 3 and see why equal partners go left to right.
2:19Column Addition and Subtraction: Carrying and Exchanging
Bruno the bear adds 476 + 358 in columns, starting with the ones and carrying when a column makes ten or more (834). Then learn exchanging for subtraction with 62 − 27, and try 503 − 168 yourself, where you have to exchange across a zero.