Speed Math for Kids Achieve Their Full Potential

(Marvins-Underground-K-12) #1
Or  like    this:

We begin from the left-hand side of the number we are dividing. Three is the first digit on the left. We
begin by asking, what do you multiply by 4 to get an answer of 3?
Three is less than 4 so we can’t evenly divide 3 by 4. So we join the 3 to the next digit, 7, to make 37.
What do we multiply by 4 to get an answer of 37? There is no whole number that gives you 37 when
you multiply it by 4. We now ask, what will give an answer just below 37? The answer is 9, because 9 ×
4 = 36. That is as close to 37 as we can get without going above. So, the answer is 9 (9 × 4 = 36), with 1
left over to make 37. One is our remainder. We would write ‘9’ above the 7 in 37 (or below, depending
on how you set out the problem). The 1 left over is carried to the next digit and put in front of it. The 1
carried changes the next number from 2 to 12.
The calculation now looks like this:


Or  like    this:

We now divide 4 into 12. What number multiplied by 4 gives an answer of 12? The answer is 3 (3 × 4
= 12). Write 3 above (or below) the 2. There is no remainder as 3 times 4 is exactly 12.
The last digit is less than 4 so it can’t be divided. Four divides into 1 zero times with 1 remainder.
The finished problem should look like this:


Or:

The 1 remainder can be expressed as a fraction, ¼. The ¼ comes from the 1 remainder over the
divisor, 4. The answer would be 930¼, or 930.25.


This     is  a   simple  method  and     should  be  carried     out     on  one     line.   It  is  easy    to  calculate   these
problems mentally this way.

Dividing numbers with decimals


How would   we  divide  567.8   by  3?
We set out the problem in the usual way.

The calculation begins as usual.
Three divides once into 5 with 2 remainder. We carry the 2 remainder to the next digit, making 26.
We write the answer, 1, below (or above) the 5 we divided. The calculation looks like this:


We now divide 26 by 3. Eight times 3 is 24, so the next digit of the answer is 8, with 2 remainder. We
carry the 2 to the 7.

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