Can someone teach me an easier way to do this sum?

[Boroncarbon]

Out of curiosity, the Daily Fail says Richard Gere is 69 & his new wife is 35 - quite a gap. I'd like to know just how big a gap? Here's how I was taught to do the sum at school:

Count from 35 up to the nearest 'whole' number (40) - so that's 5
Then jump in 10s up to 60 - so that's 20
Then add on the units above 60 - so that's 9
Then rank them in order: 20+9+5
=34

This convoluted arse-around-the-streets causes me no end of bother when wanting a quick answer. There must be a better way. I want to re-train myself to do these sums in double-quick time.

Thanks in advance.

9-5 = 4
6-3 = 3
34.

I just add 30 to 34 to get 64, then add the 5 to get to 69.

I prefer adding to subtracting so I’ll always flip sums to do them that way if I can!

70-35 =35 -1=34

69
-34

35
_
9-4=5
6-3=3

Lol no you're doing it way too complicated

69
-35

9-5 = 4
6-3 = 3

34 years gap

Count 35, 45, 55, 65 =3 jumps of 10 so 30.

65 to 69 is 4

30 and 4 = 34

I'd count on my fingers (addition)
35, 45 (one finger), 55 (next finger), 65 (third finger) so thirty. Then just know you need 4 more to get to 69. But you could do that on fingers too.

Oops I did it as if she was 34 not 35
9-5=4
6-3=3
69-35=34

Can you not just look at the lower number and see what you need to add to it to make it the higher number?

69-35=34 is how I was taught. Your way is a very long and complicated way of doing it.

I’d count on in tens first so 45, 55, 65 is 30 and then another 4 to get to 69 making 34

You know 30 to 69 is 30 though, so you don’t need to count up in tens you know you’re dealing with a 30, so just do 9-5 and add 30.

It is a sound method though it’s how we teach our lower ability maths classes in school cos you can’t really go wrong.

Also if you want to get better at these you lit just have to do loads of adding and subtracting questions. You’d still be doing basically the same steps but you’d be getting quicker.

As everyone has said 69-35=34

But you can do loads and train yourself to see patterns it took me 3 secs to notice 35 doubled was 70 so minus 1 the gap was 34.

How do you normally work out differences? Surely you just take the small number from the bigger?

35 x 2 is 70. 1 less

I'd round up the 69 to 70 and take away 35 then minus the 'roundup'.

Meadow, I think what OP is getting at is that everyone has a way of subtracting 1 from the other even though it is very subconscious.

Same as Starzig.

Also same as @starzig
69 is nearly 70. I know double 35 is 70. Take one.

Think people just do what's easiest!

For me I saw 35 and so immediately knew it was 30. And then 4 more to get to 9.

But I couldn't spell so many words even with the best formulas in the world!

I would do the same as DunesOfSand and MirandaWest - count up in tens (30) and then add on the remaining number (4).

Please tell me this thread is a wind up?