1. Near Doubles
I am learning to solve addition problems where the two numbers are easily related to doubles.
e.g = 18 Or
= 160

2. Craig has $79 and saves another $81. How much money does he have?
= ?
Step 1: Let’s use some notes and coins to represent this question.
Step 2: If we move $1 from the $79 to the $80 then both piles will have $80.
Step 3: Swap the ten $1 coins for a $10 note and then both groups have $80
= 160
$10
$10
$10 1 1
$10
$10
$10 1 1
$10
$10
$10 1 1
$10
$10
$10 1 1
$10
$10
$10 1 1
$10 1

3. Kim drove 78km on Monday and 79km on Tuesday
Kim drove 78km on Monday and 79km on Tuesday. How many kilometres has she driven?
= ?
= ……
Step 1: Let’s use our doubles to help us answer this question. Change the question into This will be much easier to answer. +2 +1
= 160
Step 2: We added 2 to the 78 and 1 to the 79 (a total of 3). So now we must subtract 3 from our answer of 160.
160 – 3 = 157

4. Now try these questions on your own.
= ?
= ?
= ?
= ?
= ?
140
Click again when you have completed each question and the answer will be displayed. 76
181
400
238
Need some more practise? Try Pg55 of Teacher Tools Addition and Subtraction Book Numeracy resources