Break apart ones to make a ten. then add and write the sum. 62 + 9 =

Step-by-step explanation:

Break Apart to make tens is a strategy to help children to add numbers in a easier way. This is applied when they have to sum 2-digits number, which is new for them.

So, first we could think about how many units in 62 are left to each 70, we'll find that 8 units are left to reach 70. So, this 8 will help to break the simplest part, which is 9, we can rewrite 9 as the sum of 8+1.

Then, the next step is add 62+8, because kids know that makes a ten, 62+8=70, now we have a ten formed. Lastly, we just add the second number missing, which is 1. 70+1=71.

You see, this strategy consist in making tens to help children to sum, because they are familiarize with sum based on tens.

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2