26 Speed Math for Kids
Th is is how I would solve this problem in my head:
16 plus 6 (from the second 16) equals 22,
times 10 equals 220
6 times 6 is 36
220 plus 30 is 250, plus 6 is 256
Try it. See how you do.
Inside your head you would say:
16 plus 6... 22... 220... 36... 256
With practice, you can leave out a lot of that. You don’t have to go
through it step by step. You would only say to yourself:
220... 256
Practice doing this. Saying the right thing in your head as you do
the calculation can better than halve the time it takes.
How would you calculate 7 × 8 in your head? You would “see” 3 and
2 below the 7 and 8. You would take 2 from the 7 (or 3 from the 8)
and say, “Fifty,” multiplying by 10 in the same step. Th ree times 2 is
- All you would say is, “Fifty... six.”
What about 6 × 7?
You would “see” 4 and 3 below the 6 and 7. Six minus 3 is 3; you
say, “Th irty.” Four times 3 is 12, plus 30 is 42. You would just say,
“Th irty... forty-two.”
It’s not as hard as it sounds, is it? And it will become easier the more
you do.
DOUBLE MULTIPLICATION
Let’s multiply 88 by 84. We use 100 as our reference number. Both
numbers are below 100, so we draw the circles below. How many
below are they? Twelve and 16. We write 12 and 16 in the circles.