1. 601.
   612.
2. 619.
   603.

Odd minus odd is always even!

1. 100.
   110.
2. 120.
   105.

This one's not too hard. We're really just warming you up here. The right answer is 105!

1. 759.
   758.
2. 760.
   748.

An even number minus a smaller odd number? That means the answer must be positive and odd.

1. 95.
   15.
2. 45.
   85.

This one, you just have to do in your head. You know from the 7 and the 2 at the ends that it ends in a 5, so your focus is on the middle number.

1. 1.
   200.
2. 400.
   2.

It's just 2! Sometimes in this quiz, we'll include questions that might look hard but are actually really easy. We don't want you to overwork here!

1. 857.
   855.
2. 858.
   859.

An even number minus a smaller even number? That means you are looking for an even answer that's still a positive integer.

1. 301.
   302.
2. 303.
   307.

An odd number minus a smaller odd number? That means the answer must be positive and even.

1. 200.
   300.
2. 277.
   177.

It's 277! It's not a hard one, but you might have worked too hard and thus landed on the wrong answer. The key is not to think too hard when you don't have to!

1. 514.
   -514.
2. 1198.
   415.

Even number minus smaller even number equals positive even number. Hence, 514.

1. 1.
   0.
2. 200.
   100.

It's a nice easy one you really can do at a glance. It's 100!

1. 78.
   979.
2. -78.
   1724.

Big number minus bigger number? The result? Negative number!

1. -621.
   621.
2. 162.
   -162.

A smaller number minus a huge number is a big negative number. Hence, -621.

1. 0.
   100.
2. 1.
   2.

Not a trick question, this one. It's just a nice clean zero!

1. -100.
   -757.
2. 757.
   -801.

We're getting some negative answers here - and they're going to get more common as we go, so look out! It's -757.

1. 801.3.
   803.7.
2. 811.6.
   811.2.

If you think of this as 822.0 minus 10.4, you instantly know you're looking for a .6. So the answer is the only one with that.

1. 101.
   10.0.
2. 1.
   17.

It's 10! We put the .0 to mess with you. We bet you didn't fall for it, though.

1. 72.2.
   79.2.
2. 73.4.
   75.9.

A round number minus an odd number is an odd number! So if you forget the decimal points for a moment, you can just see the answer at a glance.

1. 43.2.
   57.7.
2. 54.3.
   58.6.

It has to end in .7! So it's 57.7, even if you don't do the rest of the sum. Mental arithmetic is often about leaping to the conclusion via the shortcut (but, you know, do then check that it was the right instinct).

1. 0.98.
   0.28.
2. 2.98.
   3.98.

It has to end with a .28! And it has to be less than 1 total!

1. 10.01.
   9.10.
2. 11.0.
   8.01.

It has to be smaller and it has to end with .01. Hence, 8.01!

1. 102.01.
   101.99.
2. 101.02.
   101.01.

It's an integer minus something with a .01, so you know it'll end in a .99. Hence, 101.99!

1. 366.1.
   420.3.
2. 360.2.
   366.

It has to have a .1 and it has to be smaller than the original! Hence, 366.1!

1. 1.18.
   2.18.
2. 21.2.
   22.1.

It's a deduction. Just treat the decimals like you would any three-digit number to get 1.18.

1. -1.5.
   2.5.
2. 1.5.
   -.3.5.

This one's simple! It's 1.5.

1. 32.01.
   28.01.
2. 29.9.
   27.99.

Anything ending .0 that deducts something ending 0.01 has to end in .99. There's just one option!

1. 409.0.
   298.
2. 236.1.
   156.2.

It has to be 0.1 someplace because of the .9. Given the multiple choice, really you don't need to do more math than that!

1. 999.
   111.
2. 666.
   222.

Yep, it's just 111. Couldn't be simpler!

1. 0.07.
   7.
2. -0.07.
   -0.1.

It's a tiny number minus a slightly greater number. Hence, a negative result.

1. -1.
   1.
2. -199.
   199.

A negative number minus a positive number is an even more negative number. Hence -199.

1. 172.
   -816.
2. -172.
   816.

It's a negative, then minus another negative. The latter two minus signs cancel out, so you add the 494.

1. 516.
   -516.
2. 1450.
   -1450.

-1450 is the right answer, as this is a negative number minus a positive number. So you get a negative result!

1. -199.9.
   200.
2. 199.9.
   -0.1.

A negative minus a positive is two negatives. So the right answer is -199.9.

1. 110.
   110.
2. -111.
   -66.6.

Two negatives here - one negative, then a positive that is deducted. So you get -111.

1. 0.
   828.
2. 1656.
   -1656.

It's zero! You have a negative, and then a double negative. So the negative and positive cancel out for a zero.

1. 170.
   -340.
2. 0.
   340.

The first is negative, and the second is positive but you're deducting it. Hence, you end up with both being totally negative, for -340.