Decimals are multiples of 1/10 …easy to transform!
For example…you’re given: 0.4 x 550
and you think you have to multiply out and move the decimal over 1, just like you were taught. But! If you remember that multiplying by 10 and dividing by 10 on the same side cancels out…
so, it’s like multiplying by 1. Let’s just do it:
.4 x 550 >>> .4 (x 10) x 550/10 is the same as 4 x 55 which one would you rather tackle…..4 x 55 right.. 220!
You get the same answer either way, but removing the decimal makes it easier for our brains.
Try another one: .7 x 800 that’s the same as 7 x 80 which is 560!
Try some more:
.8 x 120
.9 x 60
.3 x 120
80 x .3
110 x 2.7
*Check your answers: 96, 54, 36, 24, 297