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Multiplication Using Any Reference Number 53 Our problem now looks like this: +1 +14 50 51 × 64 = 6,500 3,250 14 3,264 Answer W ...
54 Speed Math for Kids MULTIPLYING HIGHER NUMBERS Th ere is no reason why we can’t use 200, 500 and 1,000 as reference numbers. ...
Multiplication Using Any Reference Number 55 44,800 + 144 = 44,944 +12 +12 200 212 × 212 = 224 44,800 144 44,944 Answer Let’s t ...
56 Speed Math for Kids +11 +3 500 511 × 503 = 514 257,000 33 257,033 Answer Let’s try one more. 989 × 994 = We use 1,000 as the ...
Multiplication Using Any Reference Number 57 DOUBLING AND HALVING NUMBERS To use 20 and 50 as reference numbers, we need to be a ...
58 Speed Math for Kids To double 38, think of 40 – 2. Double 40 would be 80 and double –2 is –4, so we get 80 – 4, which is 76. ...
59 = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < ...
60 Speed Math for Kids Is there a way to make the method work in this case? Th ere is, but we must use a diff erent reference nu ...
Multiplying Lower Numbers 61 25 – 1 = 24 +1 5 6 × 4 = 5 –1 25 – 1 = 24 Answer Th is is a long and complicated method for multipl ...
62 Speed Math for Kids 15 + 1 = 16 5 4 × 4 = 30 –1 –1 15 1 16 Answer Test you rself Now try the following: a) 3 × 4 = d) 3 × 6 ...
Multiplying Lower Numbers 63 Test you rself Tr y the se : a) 8 × 5 = b) 4 × 5 = c) 2 × 5 = d) 6 × 5 = The answers are: a) 40 b) ...
64 Speed Math for Kids The answers are: a) 15 b) 25 c) 45 d) 35 Th is is an easy way to learn the 5 times multiplication table. ...
Multiplying Lower Numbers 65 9 6 × 4 = –3 –5 Subtract crossways: 6 – 5 = 1 or 4 – 3 = 1 Multiply 1 by our reference number, 9: 1 ...
66 Speed Math for Kids Let’s try 7 as a reference number. (^7) 6 × 4 = 3 –1 –3 21 3 24 Answer Let’s try 3 as a reference number ...
Multiplying Lower Numbers 67 Th e numbers are below 9, so we draw the circles below. How much below 9? Two and 1. Write 2 and 1 ...
68 Speed Math for Kids 11 × 4 = 44 Multiply the numbers in the circles and add the result to 44. 4 × 3 = 12 44 + 12 = 56 Answer ...
69 = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < > + - = x 0 1 2 3 4 5 6 7 8 9 ( ) % < ...
70 Speed Math for Kids Th ese calculations are easy to do in your head. If somebody asks you to multiply 72 by 11, you could imm ...
Multiplication by 11 71 Nine plus 5 is 14. We add 1 to the 9 to get 10. We work with 10 the same as we would with a single-digit ...
72 Speed Math for Kids Write 5 as the next digit of your answer. Your calculation should now look like this: 0123 × 11 53 Contin ...
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