the expression is 4(98)
2007-10-18 10:37:11 · 6 answers · asked by you-know-who 1 in Science & Mathematics ➔ Mathematics
break 98 into its components 90+8
four times ninety is 360
for times eight is 32
added together is 392
However, thinking backwords makes this easier.
98 is almost 100
4 times 100 is 400
difference of 2 times 4 is 8
Subtracting 8 from 400 gives 392...and this should be fairly easy to figure mentally.
2007-10-18 10:41:09 · answer #1 · answered by Kenneth H 3 · 0⤊ 0⤋
In you mind rewrite 98 as 100-2
Then your problem is just 4 (100-2) or using the distributive property
400-8 = 392
2007-10-18 10:42:03 · answer #2 · answered by baja_tom 4 · 0⤊ 0⤋
Even easier, 4(98) = 4(100) - 4(2) = 400 - 8 = 392.
2007-10-18 10:42:10 · answer #3 · answered by Robert 3 · 0⤊ 0⤋
98 = 100-2.
4(98) = 4(100-2) = 400-8 = 392.
2007-10-18 10:41:48 · answer #4 · answered by steiner1745 7 · 0⤊ 0⤋
4*90 + 4*8
2007-10-18 10:49:05 · answer #5 · answered by Gmoney Bling 2 · 0⤊ 0⤋
a million.ninety 9 alterations to 2-0.01 in view which you won't be able to do a million.ninety 9 situations 5 on your head. they choose you to do psychological math. 2-0.01 is comparable to a million.ninety 9 so it relatively is effective. Then it relatively is much less complicated to do something on your head.
2016-10-13 02:50:12 · answer #6 · answered by ? 4 · 0⤊ 0⤋