What you need to know

Things to remember:

  • To make addition and subtraction easier we can split our numbers into hundreds, tens and units.

Let’s see how we can split our numbers into hundreds, tens, and units to make addition easier.

24+2=20+4+2=20+6=26

313+5= 300+10+3+5=300+10+8=318

We can do the same for tens and hundreds:

356+40=300+50+6+40=300+50+40+6=300+90+6=396

219+300=200+10+9+300=200+300+10+9=500+10+9=519

Just because, sometimes when we add our units will become tens, and tens will be come hundreds!

356+60= 300+50+6+60=300+50+60+6=300+110+6=416

We can do subtractions in the exact same way!

218 - 4 = 200 + 10 + 8 - 4=200+10+4=214

256 - 20 = 200 + 50 +6-20=200 + 50 - 20 +6 = 200+30+6=236

299-100=200+90+9-100=200-100+90+9=100+90+9=199

Sometimes we need to be careful with subtractions as well. If the number we are taking away is bigger, we need to “borrow 1” from the bigger number.

532-70=500 + 30 - 70 + 2 = 400 + 130-70 +2=400+60+2=462

Example Questions

Question 1: What is 425+300?

Answer

425+300=400 + 20 + 5 + 300 = 400+300+20+5=700+20+5=725

So, the answer is 725.

Question 2: What is 265-90?

Answer

265-90=200+60-90+5=100+160-90+5=100+70+5=175