Speed Math for Kids Achieve Their Full Potential

j) 224 If any of your answers were wrong, read through this section again, find your mistake, then ...

Inside your head you would say: 16 plus 6. . . 22 . . .220 . . .36. . . 256 With practic ...

d) 7,480 Combining the methods taught in this book creates endless possibilities. Experiment for yourself. Note ...

Chapter 4 MULTIPLYING ABOVE & BELOW THE REFERENCE NUMBER Until now, we have multiplied numbers that w ...

from 63 in your head? 63 − 9 = I am sure you got the right answer, but how did you get it? Some would ...

Multiplying numbers in the circles The rule for multiplying the numbers in the circles is: When both circles are ...

Chapter 5 CHECKING YOUR ANSWERS What would it be like if you always found the right answer to every math ...

1 + 5 = 6 Six is our check answer. We add the digits of the original answer, 168: 1 + 6 + 8 = 15 Fif ...

There is another shortcut to this procedure. If we find a 9 anywhere in the calculation, we cross ...

is the same as our substitute answer so we were right again. Let’s try one more example. Let’s check i ...

Let’s try 13: 1 + 3 = 4 Four is the digit sum of 13. It should be the remainder you would get if you di ...

Chapter 6 MULTIPLICATION USING ANY REFERENCE NUMBER In Chapters 1 to 4 you learnt how to multiply numbers u ...

Checking answers Let us apply what we learnt in the last chapter and check our answer: The substitute numbers ...

We check by casting out the nines: Multiply our substitute numbers and then add the digits in the answer: 5 × 4 ...

Now let’s try the same example using 10 as a reference number: Add crossways, then multiply by 10 to get ...

Our problem now looks like this: Let’s check the answer by casting out the nines: Zero times 7 is 0, so the ...

We divide by 2 to get 3,000. We then multiply the numbers in the circles and add the result to 3,000: 3 × 7 ...

How did you go with those? You should have had no trouble doing all of them in your head. The answers are: ...

Multiply by 500. (Multiply by 1,000 and divide by 2.) 514 × 1,000 = 514,000 Half of 514,000 is 257,000. ...

c) 38 ÷ 2 = d) 94 ÷ 2 = e) 54 ÷ 2 = f) 36 ÷ 2 = g) 78 ÷ 2 = h) 56 ÷ 2 = The answers are: a) ...