just solve the solution(sum is addition and difference is for subtraction)if its easier, try switching the signs (of just the second and third)1) 53 =82)10+6 =163)7(21) =144)11+(15) = 45)99 =06)13+(2) =15however, as you can see, it sometimes makes the equation look worse (such as in number 3, 4)you can try thing of a numberline that goes into the negatives as wellsuch as in number 3, you start off with 7 but need to add 21 to find the suminstead of trying to add this, you can subtract 7 from 21 since this difference is also the same as the number you need for the sum of 7 and a number to be 21im sorry if this is confusing but its kinda hard to explaingood luck and if you have trouble, ask your teacher for more help/better explaining:]
