Match/Choose the math sentences that count up and back by tens.
47+40=88 57+30=87 46+10=56
56-10=46 87-40=47 87-30=57
Write the matching math sentences.
To find the math sentences that count up and back by tens, we need to look for addition and subtraction problems that involve adding or subtracting the number 10. Let's examine each option:
47 + 40 = 88 - This is not counting up or back by tens because we're adding 40, which is not 10.
57 + 30 = 87 - This math sentence counts up by tens because we are adding 30, which is 3 tens.
46 + 10 = 56 - This math sentence counts up by tens because we are adding the number 10.
56 - 10 = 46 - This math sentence counts back by tens because we are subtracting the number 10.
87 - 40 = 47 - This math sentence counts back by tens because we are subtracting 40, which is 4 tens.
87 - 30 = 57 - This is not counting up or back by tens because we are subtracting 30, which is not 10.
Therefore, the matching math sentences that count up and back by tens are:
57 + 30 = 87 and 87 - 40 = 47